GNU/Linux Resource List
Published: 2023-05-02 12:44:45

# GNU/Linux Resource List


#####   Shells


✅ <a href="https://www.gnu.org/software/bash/"><b>GNU Bash</b></a> - is an sh-compatible shell that incorporates useful features from the Korn shell and C shell.<br>
✅ <a href="https://www.zsh.org/"><b>Zsh</b></a> - is a shell designed for interactive use, although it is also a powerful scripting language.<br>
✅ <a href="https://tcl-lang.org/"><b>tclsh</b></a> - is a very powerful cross-platform shell, suitable for a huge range of uses.<br>
✅ <a href="https://github.com/Bash-it/bash-it"><b>bash-it</b></a> - is a framework for using, developing and maintaining shell scripts and custom commands.<br>
✅ <a href="https://ohmyz.sh/"><b>Oh My ZSH!</b></a> - is the best framework for managing your Zsh configuration.<br>
✅ <a href="https://github.com/oh-my-fish/oh-my-fish"><b>Oh My Fish</b></a> - the Fishshell framework.<br>
✅ <a href="https://github.com/starship/starship"><b>Starship</b></a> - the cross-shell prompt written in Rust.<br>
✅ <a href="https://github.com/romkatv/powerlevel10k"><b>powerlevel10k</b></a> - is a fast reimplementation of Powerlevel9k ZSH theme.<br>
</p>

#####   Shell plugins


✅ <a href="https://github.com/rupa/z"><b>z</b></a> - tracks the folder you use the most and allow you to jump, without having to type the whole path.<br>
✅ <a href="https://github.com/junegunn/fzf"><b>fzf</b></a> - is a general-purpose command-line fuzzy finder.<br>
✅ <a href="https://github.com/zsh-users/zsh-autosuggestions"><b>zsh-autosuggestions</b></a> - Fish-like autosuggestions for Zsh.<br>
✅ <a href="https://github.com/zsh-users/zsh-syntax-highlighting"><b>zsh-syntax-highlighting</b></a> - Fish shell like syntax highlighting for Zsh.<br>
✅ <a href="https://github.com/unixorn/awesome-zsh-plugins"><b>Awesome ZSH Plugins</b></a> - A list of frameworks, plugins, themes and tutorials for ZSH.<br>
</p>

#####   Managers


✅ <a href="https://midnight-commander.org/"><b>Midnight Commander</b></a> - is a visual file manager, licensed under GNU General Public License.<br>
✅ <a href="https://github.com/ranger/ranger"><b>ranger</b></a> - is a VIM-inspired filemanager for the console.<br>
✅ <a href="https://github.com/jarun/nnn"><b>nnn</b></a> - is a tiny, lightning fast, feature-packed file manager.<br>
✅ <a href="https://www.gnu.org/software/screen/"><b>screen</b></a> - is a full-screen window manager that multiplexes a physical terminal.<br>
✅ <a href="https://github.com/tmux/tmux/wiki"><b>tmux</b></a> - is a terminal multiplexer, lets you switch easily between several programs in one terminal.<br>
✅ <a href="https://github.com/peikk0/tmux-cssh"><b>tmux-cssh</b></a> - is a tool to set comfortable and easy to use functionality, clustering and synchronizing tmux-sessions.<br>
</p>

#####   Text editors


✅ <a href="http://ex-vi.sourceforge.net/"><b>vi</b></a> - is one of the most common text editors on Unix.<br>
✅ <a href="https://www.vim.org/"><b>vim</b></a> - is a highly configurable text editor.<br>
✅ <a href="https://www.gnu.org/software/emacs/"><b>emacs</b></a> - is an extensible, customizable, free/libre text editor, and more.<br>
✅ <a href="https://github.com/zyedidia/micro"><b>micro</b></a> - is a modern and intuitive terminal-based text editor.<br>
✅ <a href="https://neovim.io/"><b>neovim</b></a> - is a free open source, powerful, extensible and usable code editor.<br>
✅ <a href="https://www.spacemacs.org/"><b>spacemacs</b></a> - a community-driven Emacs distribution.<br>
✅ <a href="https://spacevim.org/"><b>spacevim</b></a> - a community-driven vim distribution.<br>
</p>

#####   Files and directories


✅ <a href="https://github.com/sharkdp/fd"><b>fd</b></a> - is a simple, fast and user-friendly alternative to find.<br>
✅ <a href="https://dev.yorhel.nl/ncdu"><b>ncdu</b></a> - is an easy to use, fast disk usage analyzer.<br>
</p>

#####   Network


✅ <a href="https://www.putty.org/"><b>PuTTY</b></a> - is an SSH and telnet client, developed originally by Simon Tatham.<br>
✅ <a href="https://mosh.org/"><b>Mosh</b></a> - is a SSH wrapper designed to keep a SSH session alive over a volatile connection.<br>
✅ <a href="https://eternalterminal.dev/"><b>Eternal Terminal</b></a> - enables mouse-scrolling and tmux commands inside the SSH session.<br>
✅ <a href="https://nmap.org/"><b>nmap</b></a> - is a free and open source (license) utility for network discovery and security auditing.<br>
✅ <a href="https://github.com/zmap/zmap"><b>zmap</b></a> - is a fast single packet network scanner designed for Internet-wide network surveys.<br>
✅ <a href="https://github.com/RustScan/RustScan"><b>Rust Scan</b></a> - to find all open ports faster than Nmap.<br>
✅ <a href="https://github.com/robertdavidgraham/masscan"><b>masscan</b></a> - is the fastest Internet port scanner, spews SYN packets asynchronously.<br>
✅ <a href="https://github.com/gvb84/pbscan"><b>pbscan</b></a> - is a faster and more efficient stateless SYN scanner and banner grabber.<br>
✅ <a href="http://www.hping.org/"><b>hping</b></a> - is a command-line oriented TCP/IP packet assembler/analyzer.<br>
✅ <a href="https://github.com/traviscross/mtr"><b>mtr</b></a> - is a tool that combines the functionality of the 'traceroute' and 'ping' programs in a single tool.<br>
✅ <a href="https://github.com/mehrdadrad/mylg"><b>mylg</b></a> - utility which combines the functions of the different network probes in one diagnostic tool.<br>
✅ <a href="http://netcat.sourceforge.net/"><b>netcat</b></a> - utility which reads and writes data across network connections, using the TCP/IP protocol.<br>
✅ <a href="http://www.dest-unreach.org/socat/"><b>socat</b></a> - utility which transfers data between two objects.<br>
✅ <a href="https://www.tcpdump.org/"><b>tcpdump</b></a> - is a powerful command-line packet analyzer.<br>
✅ <a href="https://www.wireshark.org/docs/man-pages/tshark.html"><b>tshark</b></a> - is a tool that allows us to dump and analyze network traffic (wireshark cli).<br>
✅ <a href="https://termshark.io/"><b>Termshark</b></a> - is a simple terminal user-interface for tshark.<br>
✅ <a href="https://github.com/jpr5/ngrep"><b>ngrep</b></a> - is like GNU grep applied to the network layer.<br>
✅ <a href="http://netsniff-ng.org/"><b>netsniff-ng</b></a> - is a Swiss army knife for your daily Linux network plumbing if you will.<br>
✅ <a href="https://github.com/mechpen/sockdump"><b>sockdump</b></a> - dump unix domain socket traffic.<br>
✅ <a href="https://github.com/google/stenographer"><b>stenographer</b></a> - is a packet capture solution which aims to quickly spool all packets to disk.<br>
✅ <a href="https://github.com/sachaos/tcpterm"><b>tcpterm</b></a> - visualize packets in TUI.<br>
✅ <a href="https://github.com/tgraf/bmon"><b>bmon</b></a> - is a monitoring and debugging tool to capture networking related statistics and prepare them visually.<br>
✅ <a href="http://iptraf.seul.org/2.6/manual.html#installation"><b>iptraf-ng</b></a> - is a console-based network monitoring program for Linux that displays information about IP traffic.<br>
✅ <a href="https://github.com/vergoh/vnstat"><b>vnstat</b></a> - is a network traffic monitor for Linux and BSD.<br>
✅ <a href="https://iperf.fr/"><b>iPerf3</b></a> - is a tool for active measurements of the maximum achievable bandwidth on IP networks.<br>
✅ <a href="https://github.com/Microsoft/Ethr"><b>ethr</b></a> - is a Network Performance Measurement Tool for TCP, UDP & HTTP.<br>
✅ <a href="https://github.com/jwbensley/Etherate"><b>Etherate</b></a> - is a Linux CLI based Ethernet and MPLS traffic testing tool.<br>
✅ <a href="https://github.com/mpolden/echoip"><b>echoip</b></a> - is a IP address lookup service.<br>
✅ <a href="https://github.com/troglobit/nemesis"><b>Nemesis</b></a> - packet manipulation CLI tool; craft and inject packets of several protocols.<br>
✅ <a href="https://github.com/packetfu/packetfu"><b>packetfu</b></a> - a mid-level packet manipulation library for Ruby.<br>
✅ <a href="https://scapy.net/"><b>Scapy</b></a> - packet manipulation library; forge, send, decode, capture packets of a wide number of protocols.<br>
✅ <a href="https://github.com/SecureAuthCorp/impacket"><b>impacket</b></a> - is a collection of Python classes for working with network protocols.<br>
✅ <a href="https://github.com/arthepsy/ssh-audit"><b>ssh-audit</b></a> - is a tool for SSH server auditing.<br>
✅ <a href="https://aria2.github.io/"><b>aria2</b></a> - is a lightweight multi-protocol & multi-source command-line download utility.<br>
✅ <a href="https://github.com/x-way/iptables-tracer"><b>iptables-tracer</b></a> - observe the path of packets through the iptables chains.<br>
✅ <a href="https://github.com/proabiral/inception"><b>inception</b></a> - a highly configurable tool to check for whatever you like against any number of hosts.<br>
</p>

#####   Network (DNS)


✅ <a href="https://github.com/farrokhi/dnsdiag"><b>dnsdiag</b></a> - is a DNS diagnostics and performance measurement tools.<br>
✅ <a href="https://github.com/mschwager/fierce"><b>fierce</b></a> - is a DNS reconnaissance tool for locating non-contiguous IP space.<br>
✅ <a href="https://github.com/subfinder/subfinder"><b>subfinder</b></a> - is a subdomain discovery tool that discovers valid subdomains for websites.<br>
✅ <a href="https://github.com/aboul3la/Sublist3r"><b>sublist3r</b></a> - is a fast subdomains enumeration tool for penetration testers.<br>
✅ <a href="https://github.com/OWASP/Amass"><b>amass</b></a> - is tool that obtains subdomain names by scraping data sources, crawling web archives, and more.<br>
✅ <a href="https://github.com/google/namebench"><b>namebench</b></a> - provides personalized DNS server recommendations based on your browsing history.<br>
✅ <a href="https://github.com/blechschmidt/massdns"><b>massdns</b></a> - is a high-performance DNS stub resolver for bulk lookups and reconnaissance.<br>
✅ <a href="https://github.com/guelfoweb/knock"><b>knock</b></a> - is a tool to enumerate subdomains on a target domain through a wordlist.<br>
✅ <a href="https://github.com/DNS-OARC/dnsperf"><b>dnsperf</b></a> - DNS performance testing tools.<br>
✅ <a href="https://github.com/jedisct1/dnscrypt-proxy"><b>dnscrypt-proxy 2</b></a> - a flexible DNS proxy, with support for encrypted DNS protocols.<br>
✅ <a href="https://github.com/dnsdb/dnsdbq"><b>dnsdbq</b></a> - API client providing access to passive DNS database systems.<br>
✅ <a href="https://github.com/looterz/grimd"><b>grimd</b></a> - fast dns proxy, built to black-hole internet advertisements and malware servers.<br>
</p>

#####   Network (HTTP)


✅ <a href="https://curl.haxx.se/"><b>curl</b></a> - is a command line tool and library for transferring data with URLs.<br>
✅ <a href="https://gitlab.com/davidjpeacock/kurly"><b>kurly</b></a> - is an alternative to the widely popular curl program, written in Golang.<br>
✅ <a href="https://github.com/jakubroztocil/httpie"><b>HTTPie</b></a> - is an user-friendly HTTP client.<br>
✅ <a href="https://github.com/asciimoo/wuzz"><b>wuzz</b></a> - is an interactive cli tool for HTTP inspection.<br>
✅ <a href="https://github.com/summerwind/h2spec"><b>h2spec</b></a> - is a conformance testing tool for HTTP/2 implementation.<br>
✅ <a href="https://github.com/gildasio/h2t"><b>h2t</b></a> - is a simple tool to help sysadmins to hardening their websites.<br>
✅ <a href="https://github.com/trimstray/htrace.sh"><b>htrace.sh</b></a> - is a simple Swiss Army knife for http/https troubleshooting and profiling.<br>
✅ <a href="https://github.com/reorx/httpstat"><b>httpstat</b></a> - is a tool that visualizes curl statistics in a way of beauty and clarity.<br>
✅ <a href="https://github.com/gchaincl/httplab"><b>httplab</b></a> - is an interactive web server.<br>
✅ <a href="https://lynx.browser.org/"><b>Lynx</b></a> - is a text browser for the World Wide Web.<br>
✅ <a href="https://github.com/browsh-org/browsh/"><b>Browsh</b></a> - is a fully interactive, real-time, and modern text-based browser.<br>
✅ <a href="https://github.com/dhamaniasad/HeadlessBrowsers"><b>HeadlessBrowsers</b></a> - a list of (almost) all headless web browsers in existence.<br>
✅ <a href="https://httpd.apache.org/docs/2.4/programs/ab.html"><b>ab</b></a> - is a single-threaded command line tool for measuring the performance of HTTP web servers.<br>
✅ <a href="https://www.joedog.org/siege-home/"><b>siege</b></a> - is an http load testing and benchmarking utility.<br>
✅ <a href="https://github.com/wg/wrk"><b>wrk</b></a> - is a modern HTTP benchmarking tool capable of generating significant load.<br>
✅ <a href="https://github.com/giltene/wrk2"><b>wrk2</b></a> - is a constant throughput, correct latency recording variant of wrk.<br>
✅ <a href="https://github.com/tsenart/vegeta"><b>vegeta</b></a> - is a constant throughput, correct latency recording variant of wrk.<br>
✅ <a href="https://github.com/codesenberg/bombardier"><b>bombardier</b></a> - is a fast cross-platform HTTP benchmarking tool written in Go.<br>
✅ <a href="https://github.com/cmpxchg16/gobench"><b>gobench</b></a> - http/https load testing and benchmarking tool.<br>
✅ <a href="https://github.com/rakyll/hey"><b>hey</b></a> - HTTP load generator, ApacheBench (ab) replacement, formerly known as rakyll/boom.<br>
✅ <a href="https://github.com/tarekziade/boom"><b>boom</b></a> - is a script you can use to quickly smoke-test your web app deployment.<br>
✅ <a href="https://github.com/shekyan/slowhttptest"><b>SlowHTTPTest</b></a> - is a tool that simulates some Application Layer Denial of Service attacks by prolonging HTTP.<br>
✅ <a href="https://github.com/OJ/gobuster"><b>gobuster</b></a> - is a free and open source directory/file & DNS busting tool written in Go.<br>
✅ <a href="https://github.com/ssllabs/ssllabs-scan"><b>ssllabs-scan</b></a> - command-line reference-implementation client for SSL Labs APIs.<br>
✅ <a href="https://github.com/mozilla/http-observatory"><b>http-observatory</b></a> - Mozilla HTTP Observatory cli version.<br>
</p>

#####   SSL


✅ <a href="https://www.openssl.org/"><b>openssl</b></a> - is a robust, commercial-grade, and full-featured toolkit for the TLS and SSL protocols.<br>
✅ <a href="https://gnutls.org/manual/html_node/gnutls_002dcli-Invocation.html"><b>gnutls-cli</b></a> - client program to set up a TLS connection to some other computer.<br>
✅ <a href="https://github.com/nabla-c0d3/sslyze"><b>sslyze
</b></a> - fast and powerful SSL/TLS server scanning library.<br>
✅ <a href="https://github.com/rbsec/sslscan"><b>sslscan</b></a> - tests SSL/TLS enabled services to discover supported cipher suites.<br>
✅ <a href="https://github.com/drwetter/testssl.sh"><b>testssl.sh</b></a> - testing TLS/SSL encryption anywhere on any port.<br>
✅ <a href="https://github.com/mozilla/cipherscan"><b>cipherscan</b></a> - a very simple way to find out which SSL ciphersuites are supported by a target.<br>
✅ <a href="http://www.tarsnap.com/spiped.html"><b>spiped</b></a> - is a utility for creating symmetrically encrypted and authenticated pipes between socket addresses.<br>
✅ <a href="https://github.com/certbot/certbot"><b>Certbot</b></a> - is EFF's tool to obtain certs from Let's Encrypt and (optionally) auto-enable HTTPS on your server.<br>
✅ <a href="https://github.com/FiloSottile/mkcert"><b>mkcert</b></a> - simple zero-config tool to make locally trusted development certificates with any names you'd like.<br>
✅ <a href="https://github.com/square/certstrap"><b>certstrap</b></a> - tools to bootstrap CAs, certificate requests, and signed certificates.<br>
✅ <a href="https://github.com/yassineaboukir/sublert"><b>Sublert</b></a> - is a security and reconnaissance tool to automatically monitor new subdomains.<br>
✅ <a href="https://github.com/trimstray/mkchain"><b>mkchain</b></a> - open source tool to help you build a valid SSL certificate chain.<br>
</p>

#####   Security


✅ <a href="https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/5/html/deployment_guide/ch-selinux"><b>SELinux</b></a> - provides a flexible Mandatory Access Control (MAC) system built into the Linux kernel.<br>
✅ <a href="https://wiki.ubuntu.com/AppArmor"><b>AppArmor</b></a> - proactively protects the operating system and applications from external or internal threats.<br>
✅ <a href="https://github.com/grapheneX/grapheneX"><b>grapheneX</b></a> - Automated System Hardening Framework.<br>
✅ <a href="https://github.com/dev-sec/"><b>DevSec Hardening Framework</b></a> - Security + DevOps: Automatic Server Hardening.<br>
</p>

#####   Auditing Tools


✅ <a href="https://www.ossec.net/"><b>ossec</b></a> - actively monitoring all aspects of system activity with file integrity monitoring.<br>
✅ <a href="https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/6/html/security_guide/chap-system_auditing"><b>auditd</b></a> - provides a way to track security-relevant information on your system.<br>
✅ <a href="https://www.nongnu.org/tiger/"><b>Tiger</b></a> - is a security tool that can be use both as a security audit and intrusion detection system.<br>
✅ <a href="https://cisofy.com/lynis/"><b>Lynis</b></a> - battle-tested security tool for systems running Linux, macOS, or Unix-based operating system.<br>
✅ <a href="https://github.com/rebootuser/LinEnum"><b>LinEnum</b></a> - scripted Local Linux Enumeration & Privilege Escalation Checks.<br>
✅ <a href="https://github.com/installation/rkhunter"><b>Rkhunter</b></a> - scanner tool for Linux systems that scans backdoors, rootkits and local exploits on your systems.<br>
✅ <a href="https://github.com/hasherezade/pe-sieve"><b>PE-sieve</b></a> - is a light-weight tool that helps to detect malware running on the system.<br>
</p>

#####   System Diagnostics/Debuggers


✅ <a href="https://github.com/strace/strace"><b>strace</b></a> - diagnostic, debugging and instructional userspace utility for Linux.<br>
✅ <a href="http://dtrace.org/blogs/about/"><b>DTrace</b></a> - is a performance analysis and troubleshooting tool.<br>
✅ <a href="https://en.wikipedia.org/wiki/Ltrace"><b>ltrace</b></a> - is a library call tracer, used to trace calls made by programs to library functions.<br>
✅ <a href="https://github.com/brainsmoke/ptrace-burrito"><b>ptrace-burrito</b></a> - is a friendly wrapper around ptrace.<br>
✅ <a href="https://github.com/brendangregg/perf-tools"><b>perf-tools</b></a> - performance analysis tools based on Linux perf_events (aka perf) and ftrace.<br>
✅ <a href="https://github.com/iovisor/bpftrace"><b>bpftrace</b></a> - high-level tracing language for Linux eBPF.<br>
✅ <a href="https://github.com/draios/sysdig"><b>sysdig</b></a> - system exploration and troubleshooting tool with first class support for containers.<br>
✅ <a href="http://www.valgrind.org/"><b>Valgrind</b></a> - is an instrumentation framework for building dynamic analysis tools.<br>
✅ <a href="https://github.com/gperftools/gperftools"><b>gperftools</b></a> - high-performance multi-threaded malloc() implementation, plus some performance analysis tools.<br>
✅ <a href="https://nicolargo.github.io/glances/"><b>glances</b></a> - cross-platform system monitoring tool written in Python.<br>
✅ <a href="https://github.com/hishamhm/htop"><b>htop</b></a> - interactive text-mode process viewer for Unix systems. It aims to be a better 'top'.<br>
✅ <a href="https://github.com/aristocratos/bashtop"><b>bashtop</b></a> - Linux resource monitor written in pure Bash.<br>
✅ <a href="http://nmon.sourceforge.net/pmwiki.php"><b>nmon</b></a> - a single executable for performance monitoring and data analysis.<br>
✅ <a href="https://www.atoptool.nl/"><b>atop</b></a> - ASCII performance monitor. Includes statistics for CPU, memory, disk, swap, network, and processes.<br>
✅ <a href="https://en.wikipedia.org/wiki/Lsof"><b>lsof</b></a> - displays in its output information about files that are opened by processes.<br>
✅ <a href="http://www.brendangregg.com/flamegraphs.html"><b>FlameGraph</b></a> - stack trace visualizer.<br>
✅ <a href="https://github.com/zevv/lsofgraph"><b>lsofgraph</b></a> - convert Unix lsof output to a graph showing FIFO and UNIX interprocess communication.<br>
✅ <a href="https://github.com/mozilla/rr"><b>rr</b></a> - is a lightweight tool for recording, replaying and debugging execution of applications.<br>
✅ <a href="https://pcp.io/index.html"><b>Performance Co-Pilot</b></a> - a system performance analysis toolkit.<br>
✅ <a href="https://github.com/sharkdp/hexyl"><b>hexyl</b></a> - a command-line hex viewer.<br>
</p>

#####   Log Analyzers


✅ <a href="https://github.com/rcoh/angle-grinder"><b>angle-grinder</b></a> - slice and dice log files on the command line.<br>
✅ <a href="https://lnav.org"><b>lnav</b></a> - log file navigator with search and automatic refresh.<br>
✅ <a href="https://goaccess.io/"><b>GoAccess</b></a> - real-time web log analyzer and interactive viewer that runs in a terminal.<br>
✅ <a href="https://github.com/lebinh/ngxtop"><b>ngxtop</b></a> - real-time metrics for nginx server.<br>
</p>

#####   Databases


✅ <a href="https://github.com/xo/usql"><b>usql</b></a> - universal command-line interface for SQL databases.<br>
✅ <a href="https://github.com/dbcli/pgcli"><b>pgcli</b></a> - postgres CLI with autocompletion and syntax highlighting.<br>
✅ <a href="https://github.com/dbcli/mycli"><b>mycli</b></a> - terminal client for MySQL with autocompletion and syntax highlighting.<br>
✅ <a href="https://github.com/dbcli/litecli"><b>litecli</b></a> - SQLite CLI with autocompletion and syntax highlighting.<br>
  ✅ <a href="https://github.com/dbcli/mssql-cli"><b>mssql-cli</b></a> - SQL Server CLI with autocompletion and syntax highlighting.<br>
✅ <a href="https://github.com/osquery/osquery"><b>OSQuery</b></a> - is a SQL powered operating system instrumentation, monitoring, and analytics framework.<br>
✅ <a href="https://github.com/ankane/pgsync"><b>pgsync</b></a> - sync data from one Postgres database to another.<br>
✅ <a href="https://github.com/laixintao/iredis"><b>iredis</b></a> - a terminal client for redis with autocompletion and syntax highlighting.<br>
</p>

#####   TOR


✅ <a href="https://github.com/GouveaHeitor/nipe"><b>Nipe</b></a> - script to make Tor Network your default gateway.<br>
✅ <a href="https://github.com/trimstray/multitor"><b>multitor</b></a> - a tool that lets you create multiple TOR instances with a load-balancing.<br>
</p>

#####   Messengers/IRC Clients


✅ <a href="https://irssi.org"><b>Irssi</b></a> - is a free open source terminal based IRC client.<br>
✅ <a href="https://weechat.org/"><b>WeeChat</b></a> - is an extremely extensible and lightweight IRC client.<br>
</p>

#####   Productivity


✅ <a href="https://taskwarrior.org"><b>taskwarrior</b></a> - task management system, todo list <br>
</p>

#####   Other


✅ <a href="https://github.com/skx/sysadmin-util"><b>sysadmin-util</b></a> - tools for Linux/Unix sysadmins.<br>
✅ <a href="http://inotify.aiken.cz/"><b>incron</b></a> - is an inode-based filesystem notification technology.<br>
✅ <a href="https://github.com/axkibe/lsyncd"><b>lsyncd</b></a> - synchronizes local directories with remote targets (Live Syncing Daemon).<br>
✅ <a href="https://github.com/rgburke/grv"><b>GRV</b></a> - is a terminal based interface for viewing Git repositories.<br>
✅ <a href="https://jonas.github.io/tig/"><b>Tig</b></a> - text-mode interface for Git.<br>
✅ <a href="https://github.com/tldr-pages/tldr"><b>tldr</b></a> - simplified and community-driven man pages.<br>
✅ <a href="https://github.com/mholt/archiver"><b>archiver</b></a> - easily create and extract .zip, .tar, .tar.gz, .tar.bz2, .tar.xz, .tar.lz4, .tar.sz, and .rar.<br>
✅ <a href="https://github.com/tj/commander.js"><b>commander.js</b></a> - minimal CLI creator in JavaScript.<br>
✅ <a href="https://github.com/tomnomnom/gron"><b>gron</b></a> - make JSON greppable!<br>
✅ <a href="https://github.com/itchyny/bed"><b>bed</b></a> - binary editor written in Go.<br>
</p>

#### GUI Tools [<sup>[TOC]</sup>](#anger-table-of-contents)

#####   Terminal emulators


✅ <a href="https://github.com/Guake/guake"><b>Guake</b></a> - is a dropdown terminal made for the GNOME desktop environment.<br>
✅ <a href="https://gnometerminator.blogspot.com/p/introduction.html"><b>Terminator</b></a> - is based on GNOME Terminal, useful features for sysadmins and other users.<br>
✅ <a href="https://sw.kovidgoyal.net/kitty/"><b>Kitty</b></a> - is a GPU based terminal emulator that supports smooth scrolling and images.<br>
✅ <a href="https://github.com/alacritty/alacritty"><b>Alacritty</b></a> - is a fast, cross-platform, OpenGL terminal emulator.<br>
</p>

#####   Network


✅ <a href="https://www.wireshark.org/"><b>Wireshark</b></a> - is the world’s foremost and widely-used network protocol analyzer.<br>
✅ <a href="https://www.ettercap-project.org/"><b>Ettercap</b></a> - is a comprehensive network monitor tool.<br>
✅ <a href="https://etherape.sourceforge.io/"><b>EtherApe</b></a> - is a graphical network monitoring solution.<br>
✅ <a href="https://packetsender.com/"><b>Packet Sender</b></a> - is a networking utility for packet generation and built-in UDP/TCP/SSL client and servers.<br>
✅ <a href="https://ostinato.org/"><b>Ostinato</b></a> - is a packet crafter and traffic generator.<br>
✅ <a href="https://jmeter.apache.org/"><b>JMeter™</b></a> - open source software to load test functional behavior and measure performance.<br>
✅ <a href="https://github.com/locustio/locust"><b>locust</b></a> - scalable user load testing tool written in Python.<br>
</p>

#####   Browsers


✅ <a href="https://www.torproject.org/"><b>TOR Browser</b></a> - protect your privacy and defend yourself against network surveillance and traffic analysis.<br>
</p>

#####   Password Managers


✅ <a href="https://keepassxc.org/"><b>KeePassXC</b></a> - store your passwords safely and auto-type them into your everyday websites and apps.<br>
✅ <a href="https://bitwarden.com/"><b>Bitwarden</b></a> - open source password manager with built-in sync.<br>
</p>

#####   Messengers/IRC Clients


✅ <a href="https://hexchat.github.io/index.html"><b>HexChat</b></a> - is an IRC client based on XChat.<br>
✅ <a href="https://pidgin.im/"><b>Pidgin</b></a> - is an easy to use and free chat client used by millions.<br>
</p>

#####   Messengers (end-to-end encryption)


✅ <a href="https://www.signal.org/"><b>Signal</b></a> - is an encrypted communications app.<br>
✅ <a href="https://wire.com/en/"><b>Wire</b></a> - secure messaging, file sharing, voice calls and video conferences. All protected with end-to-end encryption.<br>
✅ <a href="https://github.com/prof7bit/TorChat"><b>TorChat</b></a> - decentralized anonymous instant messenger on top of Tor Hidden Services.<br>
✅ <a href="https://matrix.org/"><b>Matrix</b></a> - an open network for secure, decentralized, real-time communication.<br>
</p>

#####   Text editors


✅ <a href="https://www.sublimetext.com/3"><b>Sublime Text</b></a> - is a lightweight, cross-platform code editor known for its speed, ease of use.<br>
✅ <a href="https://code.visualstudio.com/"><b>Visual Studio Code</b></a> - an open-source and free source code editor developed by Microsoft.<br>
✅ <a href="https://atom.io/"><b>Atom</b></a> - a hackable text editor for the 21st Century.<br>
</p>

#### Web Tools [<sup>[TOC]</sup>](#anger-table-of-contents)

#####   Browsers


✅ <a href="https://www.ssllabs.com/ssltest/viewMyClient.html"><b>SSL/TLS Capabilities of Your Browser</b></a> - test your browser's SSL implementation.<br>
✅ <a href="https://caniuse.com/"><b>Can I use</b></a> - provides up-to-date browser support tables for support of front-end web technologies.<br>
✅ <a href="https://panopticlick.eff.org/"><b>Panopticlick 3.0</b></a> - is your browser safe against tracking?<br>
✅ <a href="https://privacy.net/analyzer/"><b>Privacy Analyzer</b></a> - see what data is exposed from your browser.<br>
✅ <a href="https://browserleaks.com/"><b>Web Browser Security</b></a> - it's all about Web Browser fingerprinting.<br>
✅ <a href="https://www.howsmyssl.com/"><b>How's My SSL?</b></a> - help a web server developer learn what real world TLS clients were capable of.<br>
✅ <a href="https://suche.org/sslClientInfo"><b>sslClientInfo</b></a> - client test (incl TLSv1.3 information).<br>
</p>

#####   SSL/Security


✅ <a href="https://www.ssllabs.com/ssltest/"><b>SSLLabs Server Test</b></a> - performs a deep analysis of the configuration of any SSL web server.<br>
✅ <a href="https://dev.ssllabs.com/ssltest/"><b>SSLLabs Server Test (DEV)</b></a> - performs a deep analysis of the configuration of any SSL web server.<br>
✅ <a href="https://www.immuniweb.com/ssl/"><b>ImmuniWeb® SSLScan</b></a> - test SSL/TLS (PCI DSS, HIPAA and NIST).<br>
✅ <a href="https://www.jitbit.com/sslcheck/"><b>SSL Check</b></a> - scan your website for non-secure content.<br>
✅ <a href="http://www.ssltools.com"><b>SSL Scanner</b></a> - analyze website security.<br>
✅ <a href="https://cryptcheck.fr/"><b>CryptCheck</b></a> - test your TLS server configuration (e.g. ciphers).<br>
✅ <a href="https://urlscan.io/"><b>urlscan.io</b></a> - service to scan and analyse websites.<br>
✅ <a href="https://report-uri.com/home/tools"><b>Report URI</b></a> - monitoring security policies like CSP and HPKP.<br>
✅ <a href="https://csp-evaluator.withgoogle.com/"><b>CSP Evaluator</b></a> - allows developers and security experts to check if a Content Security Policy.<br>
✅ <a href="https://uselesscsp.com/"><b>Useless CSP</b></a> - public list about CSP in some big players (might make them care a bit more).<br>
✅ <a href="https://whynohttps.com/"><b>Why No HTTPS?</b></a> - top 100 websites by Alexa rank not automatically redirecting insecure requests.<br>
✅ <a href="https://ciphersuite.info/"><b>TLS Cipher Suite Search</b></a>- cipher suite search engine.<br>
✅ <a href="https://github.com/RaymiiOrg/cipherli.st"><b>cipherli.st</b></a> - strong ciphers for Apache, Nginx, Lighttpd, and more.<b>*</b><br>
✅ <a href="https://2ton.com.au/dhtool/"><b>dhtool</b></a> - public Diffie-Hellman parameter service/tool.<br>
✅ <a href="https://badssl.com/"><b>badssl.com</b></a> - memorable site for testing clients against bad SSL configs.<br>
✅ <a href="https://tlsfun.de/"><b>tlsfun.de</b></a> - registered for various tests regarding the TLS/SSL protocol.<br>
✅ <a href="https://sslmate.com/caa/"><b>CAA Record Helper</b></a> - generate a CAA policy.<br>
✅ <a href="https://ccadb.org/resources"><b>Common CA Database</b></a> - repository of information about CAs, and their root and intermediate certificates.<br>
✅ <a href="https://certstream.calidog.io/"><b>CERTSTREAM</b></a> - real-time certificate transparency log update stream.<br>
✅ <a href="https://crt.sh/"><b>crt.sh</b></a> - discovers certificates by continually monitoring all of the publicly known CT.<br>
✅ <a href="https://www.hardenize.com/"><b>Hardenize</b></a> - deploy the security standards.<br>
✅ <a href="https://cryptcheck.fr/suite/"><b>Cipher suite compatibility</b></a> - test TLS cipher suite compatibility.<br>
✅ <a href="https://www.urlvoid.com/"><b>urlvoid</b></a> - this service helps you detect potentially malicious websites.<br>
✅ <a href="https://securitytxt.org/"><b>security.txt</b></a> - a proposed standard (generator) which allows websites to define security policies.<br>
✅ <a href="https://github.com/mozilla/ssl-config-generator"><b>ssl-config-generator</b></a> - help you follow the Mozilla Server Side TLS configuration guidelines.<br>
</p>

#####   HTTP Headers & Web Linters


✅ <a href="https://securityheaders.com/"><b>Security Headers</b></a> - analyse the HTTP response headers (with rating system to the results).<br>
✅ <a href="https://observatory.mozilla.org/"><b>Observatory by Mozilla</b></a> - set of tools to analyze your website.<br>
✅ <a href="https://webhint.io/"><b>webhint</b></a> - is a linting tool that will help you with your site's accessibility, speed, security, and more.<br>
</p>

#####   DNS


✅ <a href="http://viewdns.info/"><b>ViewDNS</b></a> - one source for free DNS related tools and information.<br>
✅ <a href="https://dnslookup.org/"><b>DNSLookup</b></a> - is an advanced DNS lookup tool.<br>
✅ <a href="https://dnslytics.com/"><b>DNSlytics</b></a> - online DNS investigation tool.<br>
✅ <a href="https://dnsspy.io/"><b>DNS Spy</b></a> - monitor, validate and verify your DNS configurations.<br>
✅ <a href="https://zonemaster.iis.se/en/"><b>Zonemaster</b></a> - helps you to control how your DNS works.<br>
✅ <a href="http://leafdns.com/"><b>Leaf DNS</b></a> - comprehensive DNS tester.<br>
✅ <a href="https://findsubdomains.com/"><b>Find subdomains online</b></a> - find subdomains for security assessment penetration test.<br>
✅ <a href="https://dnsdumpster.com/"><b>DNSdumpster</b></a> - dns recon & research, find & lookup dns records.<br>
✅ <a href="https://dnstable.com/"><b>DNS Table online</b></a> - search for DNS records by domain, IP, CIDR, ISP.<br>
✅ <a href="https://intodns.com/"><b>intoDNS</b></a> - DNS and mail server health checker.<br>
✅ <a href="http://www.zonecut.net/dns/"><b>DNS Bajaj</b></a> - check the delegation of your domain.<br>
✅ <a href="https://www.buddyns.com/delegation-lab/"><b>BuddyDNS Delegation LAB</b></a> - check, trace and visualize delegation of your domain.<br>
✅ <a href="https://dnssec-debugger.verisignlabs.com/"><b>dnssec-debugger</b></a> - DS or DNSKEY records validator.<br>
✅ <a href="http://ptrarchive.com/"><b>PTRarchive.com</b></a> - this site is responsible for the safekeeping of historical reverse DNS records.<br>
✅ <a href="http://xip.io/"><b>xip.io</b></a> - wildcard DNS for everyone.<br>
✅ <a href="https://nip.io/"><b>nip.io</b></a> - dead simple wildcard DNS for any IP Address.<br>
✅ <a href="https://ceipam.eu/en/dnslookup.php"><b>dnslookup (ceipam)</b></a> - one of the best DNS propagation checker (and not only).<br>
✅ <a href="https://whatsmydns.com"><b>What's My DNS</b></a> - DNS propagation checking tool.<br>
✅ <a href="https://blog.erbbysam.com/index.php/2019/02/09/dnsgrep/"><b>DNSGrep</b></a> - quickly searching large DNS datasets.<br>
</p>

#####   Mail


✅ <a href="https://luxsci.com/smtp-tls-checker"><b>smtp-tls-checker</b></a> - check an email domain for SMTP TLS support.<br>
✅ <a href="https://mxtoolbox.com/SuperTool.aspx"><b>MX Toolbox</b></a> - all of your MX record, DNS, blacklist and SMTP diagnostics in one integrated tool.<br>
✅ <a href="https://www.checktls.com/index.html"><b>Secure Email</b></a> - complete email test tools for email technicians.<br>
✅ <a href="http://www.blacklistalert.org/"><b>blacklistalert</b></a> - checks to see if your domain is on a Real Time Spam Blacklist.<br>
✅ <a href="http://multirbl.valli.org/"><b>MultiRBL</b></a> - complete IP check for sending Mailservers.<br>
✅ <a href="https://dkimvalidator.com/"><b>DKIM SPF & Spam Assassin Validator</b></a> - checks mail authentication and scores messages with Spam Assassin.<br>
</p>

#####   Encoders/Decoders and Regex testing


✅ <a href="https://www.url-encode-decode.com/"><b>URL Encode/Decode</b></a> - tool from above to either encode or decode a string of text.<br>
✅ <a href="https://uncoder.io/"><b>Uncoder</b></a> - the online translator for search queries on log data.<br>
✅ <a href="https://regex101.com/"><b>Regex101</b></a> - online regex tester and debugger: PHP, PCRE, Python, Golang and JavaScript.<br>
✅ <a href="https://regexr.com/"><b>RegExr</b></a> - online tool to learn, build, & test Regular Expressions (RegEx / RegExp).<br>
✅ <a href="https://www.regextester.com/"><b>RegEx Testing</b></a> - online regex testing tool.<br>
✅ <a href="https://www.regexpal.com/"><b>RegEx Pal</b></a> - online regex testing tool + other tools.<br>
✅ <a href="https://gchq.github.io/CyberChef/"><b>The Cyber Swiss Army Knife</b></a> - a web app for encryption, encoding, compression and data analysis.<br>
</p>

#####   Net-tools


✅ <a href="https://toolbar.netcraft.com/site_report"><b>Netcraft</b></a> - detailed report about the site, helping you to make informed choices about their integrity.<b>*</b><br>
✅ <a href="https://atlas.ripe.net/"><b>RIPE NCC Atlas</b></a> - a global, open, distributed Internet measurement platform.<br>
✅ <a href="https://www.robtex.com/"><b>Robtex</b></a> - uses various sources to gather public information about IP numbers, domain names, host names, etc.<br>
✅ <a href="https://securitytrails.com/"><b>Security Trails</b></a> - APIs for Security Companies, Researchers and Teams.<br>
✅ <a href="https://tools.keycdn.com/curl"><b>Online Curl</b></a> - curl test, analyze HTTP Response Headers.<br>
✅ <a href="https://extendsclass.com/"><b>Online Tools for Developers</b></a> - HTTP API tools, testers, encoders, converters, formatters, and other tools.<br>
✅ <a href="https://ping.eu/"><b>Ping.eu</b></a> - online Ping, Traceroute, DNS lookup, WHOIS and others.<br>
✅ <a href="https://network-tools.com/"><b>Network-Tools</b></a> - network tools for webmasters, IT technicians & geeks.<br>
✅ <a href="https://bgpview.io/"><b>BGPview</b></a> - search for any ASN, IP, Prefix or Resource name.<br>
✅ <a href="https://isbgpsafeyet.com/"><b>Is BGP safe yet?</b></a> - check BGP (RPKI) security of ISPs and other major Internet players.<br>
✅ <a href="https://riseup.net/"><b>Riseup</b></a> - provides online communication tools for people and groups working on liberatory social change.<br>
✅ <a href="https://www.virustotal.com/gui/home/upload"><b>VirusTotal</b></a> - analyze suspicious files and URLs to detect types of malware.<br>
</p>

#####   Privacy


✅ <a href="https://www.privacytools.io/"><b>privacytools.io</b></a> - provides knowledge and tools to protect your privacy against global mass surveillance.<br>
✅ <a href="https://dnsprivacy.org/wiki/display/DP/DNS+Privacy+Test+Servers"><b>DNS Privacy Test Servers</b></a> - DNS privacy recursive servers list (with a 'no logging' policy).<br>
</p>

#####   Code parsers/playgrounds


✅ <a href="https://www.shellcheck.net/"><b>ShellCheck</b></a> - finds bugs in your shell scripts.<br>
✅ <a href="https://explainshell.com/"><b>explainshell</b></a> - get interactive help texts for shell commands.<br>
✅ <a href="https://jsbin.com/?html,output"><b>jsbin</b></a> - live pastebin for HTML, CSS & JavaScript, and more.<br>
✅ <a href="https://codesandbox.io/"><b>CodeSandbox</b></a> - online code editor for web application development.<br>
✅ <a href="http://sandbox.onlinephpfunctions.com/"><b>PHP Sandbox</b></a> - test your PHP code with this code tester.<br>
✅ <a href="https://www.repl.it/"><b>Repl.it</b></a> - an instant IDE to learn, build, collaborate, and host all in one place.<br>
✅ <a href="http://www.vclfiddle.net/"><b>vclFiddle</b></a> - is an online tool for experimenting with the Varnish Cache VCL.<br>
</p>

#####   Performance


✅ <a href="https://gtmetrix.com/"><b>GTmetrix</b></a> - analyze your site’s speed and make it faster.<br>
✅ <a href="https://performance.sucuri.net/"><b>Sucuri loadtimetester</b></a> - test here the
performance of any of your sites from across the globe.<br>
✅ <a href="https://tools.pingdom.com/"><b>Pingdom Tools</b></a> - analyze your site’s speed around the world.<br>
✅ <a href="https://pingme.io/"><b>PingMe.io</b></a> - run website latency tests across multiple geographic regions.<br>
✅ <a href="https://developers.google.com/speed/pagespeed/insights/"><b>PageSpeed Insights</b></a> - analyze your site’s speed and make it faster.<br>
✅ <a href="https://web.dev/"><b>web.dev</b></a> - helps developers like you learn and apply the web's modern capabilities to your own sites and apps.<br>
✅ <a href="https://github.com/GoogleChrome/lighthouse"><b>Lighthouse</b></a> - automated auditing, performance metrics, and best practices for the web.<br>
</p>

#####   Mass scanners (search engines)


✅ <a href="https://censys.io/"><b>Censys</b></a> - platform that helps information security practitioners discover, monitor, and analyze devices.<br>
✅ <a href="https://www.shodan.io/"><b>Shodan</b></a> - the world's first search engine for Internet-connected devices.<br>
✅ <a href="https://2000.shodan.io/#/"><b>Shodan 2000</b></a> - this tool looks for randomly generated data from Shodan.<br>
✅ <a href="https://viz.greynoise.io/table"><b>GreyNoise</b></a> - mass scanner such as Shodan and Censys.<br>
✅ <a href="https://www.zoomeye.org/"><b>ZoomEye</b></a> - search engine for cyberspace that lets the user find specific network components.<br>
✅ <a href="https://netograph.io/"><b>netograph</b></a> - tools to monitor and understand deep structure of the web.<br>
✅ <a href="https://fofa.so/"><b>FOFA</b></a> - is a cyberspace search engine.<br>
✅ <a href="https://www.onyphe.io/"><b>onyphe</b></a> - is a search engine for open-source and cyber threat intelligence data collected.<br>
✅ <a href="https://intelx.io/"><b>IntelligenceX</b></a> - is a search engine and data archive.<br>
✅ <a href="https://app.binaryedge.io/"><b>binaryedge</b></a> - it scan the entire internet space and create real-time threat intelligence streams and reports.<br>
✅ <a href="https://spyse.com/"><b>Spyse</b></a> - Internet assets registry: networks, threats, web objects, etc.<br>
✅ <a href="https://wigle.net/"><b>wigle</b></a> - is a submission-based catalog of wireless networks. All the networks. Found by Everyone.<br>
✅ <a href="https://publicwww.com/"><b>PublicWWW</b></a> - find any alphanumeric snippet, signature or keyword in the web pages HTML, JS and CSS code.<br>
✅ <a href="https://inteltechniques.com/index.html"><b>IntelTechniques</b></a> - this repository contains hundreds of online search utilities.<br>
✅ <a href="https://hunter.io/"><b>hunter</b></a> - lets you find email addresses in seconds and connect with the people that matter for your business.<br>
✅ <a href="https://ghostproject.fr/"><b>GhostProject?</b></a> - search by full email address or username.<br>
✅ <a href="https://www.databreaches.live/"><b>databreaches</b></a> - was my email affected by data breach?<br>
✅ <a href="https://weleakinfo.com"><b>We Leak Info</b></a> - world's fastest and largest data breach search engine.<br>
✅ <a href="https://pulsedive.com/"><b>Pulsedive</b></a> - scans of malicious URLs, IPs, and domains, including port scans and web requests.<br>
✅ <a href="https://buckets.grayhatwarfare.com/"><b>Buckets by Grayhatwarfar</b></a> - database with public search for Open Amazon S3 Buckets and their contents.<br>
✅ <a href="https://vigilante.pw/"><b>Vigilante.pw</b></a> - the breached database directory.<br>
✅ <a href="https://builtwith.com/"><b>builtwith</b></a> - find out what websites are built with.<br>
✅ <a href="https://nerdydata.com/"><b>NerdyData</b></a> - search the web's source code for technologies, across millions of sites.<br>
✅ <a href="http://zorexeye.com/"><b>zorexeye</b></a> - search for sites, images, apps, softwares & more.<br>
✅ <a href="https://www.mmnt.net/"><b>Mamont's open FTP Index</b></a> - if a target has an open FTP site with accessible content it will be listed here.<br>
✅ <a href="https://osintframework.com/"><b>OSINT Framework</b></a> - focused on gathering information from free tools or resources.<br>
✅ <a href="https://www.maltiverse.com/search"><b>maltiverse</b></a> - is a service oriented to cybersecurity analysts for the advanced analysis of indicators of compromise.<br>
✅ <a href="https://leakedsource.ru/main/"><b>Leaked Source</b></a> - is a collaboration of data found online in the form of a lookup.<br>
✅ <a href="https://search.weleakinfo.com/"><b>We Leak Info</b></a> - to help everyday individuals secure their online life, avoiding getting hacked.<br>
✅ <a href="https://pipl.com/"><b>pipl</b></a> - is the place to find the person behind the email address, social username or phone number.<br>
✅ <a href="https://abuse.ch/"><b>abuse.ch</b></a> - is operated by a random swiss guy fighting malware for non-profit.<br>
✅ <a href="http://malc0de.com/database/"><b>malc0de</b></a> - malware search engine.<br>
✅ <a href="https://cybercrime-tracker.net/index.php"><b>Cybercrime Tracker</b></a> - monitors and tracks various malware families that are used to perpetrate cyber crimes.<br>
✅ <a href="https://github.com/eth0izzle/shhgit/"><b>shhgit</b></a> - find GitHub secrets in real time.<br>
✅ <a href="https://searchcode.com/"><b>searchcode</b></a> - helping you find real world examples of functions, API's and libraries.<br>
✅ <a href="http://www.insecam.org/"><b>Insecam</b></a> - the world biggest directory of online surveillance security cameras.<br>
✅ <a href="http://index-of.es/"><b>index-of</b></a> - contains great stuff like: security, hacking, reverse engineering, cryptography, programming etc.<br>
✅ <a href="https://opendata.rapid7.com/"><b>Rapid7 Labs Open Data</b></a> - is a great resources of datasets from Project Sonar.<br>
✅ <a href="https://webtechsurvey.com/common-response-headers"><b>Common Response Headers</b></a> - the largest database of HTTP response headers.<br>
</p>

#####   Generators


✅ <a href="https://thispersondoesnotexist.com/"><b>thispersondoesnotexist</b></a> - generate fake faces in one click - endless possibilities.<br>
✅ <a href="https://generated.photos"><b>AI Generated Photos</b></a> - 100.000 AI generated faces.<br>
✅ <a href="https://www.fakenamegenerator.com/"><b>fakenamegenerator</b></a> - your randomly generated identity.<br>
✅ <a href="https://tools.intigriti.io/redirector/"><b>Intigriti Redirector</b></a> - open redirect/SSRF payload generator.<br>
</p>

#####   Passwords


✅ <a href="https://haveibeenpwned.com/"><b>have i been pwned?</b></a> - check if you have an account that has been compromised in a data breach.<br>
✅ <a href="https://www.dehashed.com/"><b>dehashed</b></a> - is a hacked database search engine.<br>
✅ <a href="https://leakedsource.ru/"><b>Leaked Source</b></a> - is a collaboration of data found online in the form of a lookup.<br>
</p>

#####   CVE/Exploits databases


✅ <a href="https://cve.mitre.org/"><b>CVE Mitre</b></a> - list of publicly known cybersecurity vulnerabilities.<br>
✅ <a href="https://www.cvedetails.com/"><b>CVE Details</b></a> - CVE security vulnerability advanced database.<br>
✅ <a href="https://www.exploit-db.com/"><b>Exploit DB</b></a> - CVE compliant archive of public exploits and corresponding vulnerable software.<br>
✅ <a href="https://0day.today/"><b>0day.today</b></a> - exploits market provides you the possibility to buy/sell zero-day exploits.<br>
✅ <a href="https://sploitus.com/"><b>sploitus</b></a> - the exploit and tools database.<br>
✅ <a href="https://cxsecurity.com/exploit/"><b>cxsecurity</b></a> - free vulnerability database.<br>
✅ <a href="https://www.vulncode-db.com/"><b>Vulncode-DB</b></a> - is a database for vulnerabilities and their corresponding source code if available.<br>
✅ <a href="https://cveapi.com/"><b>cveapi</b></a> - free API for CVE data.<br>
</p>

#####   Mobile apps scanners


✅ <a href="https://www.immuniweb.com/mobile/"><b>ImmuniWeb® Mobile App Scanner</b></a> - test security and privacy of mobile apps (iOS & Android).<br>
✅ <a href="https://vulnerabilitytest.quixxi.com/"><b>Quixxi</b></a> - free Mobile App Vulnerability Scanner for Android & iOS.<br>
✅ <a href="https://www.ostorlab.co/scan/mobile/"><b>Ostorlab</b></a> - analyzes mobile application to identify vulnerabilities and potential weaknesses.<br>
</p>

#####   Private Search Engines


✅ <a href="https://www.startpage.com/"><b>Startpage</b></a> - the world's most private search engine.<br>
✅ <a href="https://searx.me/"><b>searX</b></a> - a privacy-respecting, hackable metasearch engine.<br>
✅ <a href="https://darksearch.io/"><b>darksearch</b></a> - the 1st real Dark Web search engine.<br>
✅ <a href="https://www.qwant.com/"><b>Qwant</b></a> - the search engine that respects your privacy.<br>
✅ <a href="https://duckduckgo.com/"><b>DuckDuckGo</b></a> - the search engine that doesn't track you.<br>
✅ <a href="https://swisscows.com/"><b>Swisscows</b></a> - privacy safe web search<br>
✅ <a href="https://search.disconnect.me/"><b>Disconnect</b></a> - the search engine that anonymizes your searches.<br>
✅ <a href="https://metager.org/"><b>MetaGer</b></a> - the search engine that uses anonymous proxy and hidden Tor branches.<br>
</p>

#####   Secure Webmail Providers


✅ <a href="https://countermail.com/"><b>CounterMail</b></a> - online email service, designed to provide maximum security and privacy.<br>
✅ <a href="http://mail2tor.com/"><b>Mail2Tor</b></a> - is a Tor Hidden Service that allows anyone to send and receive emails anonymously.<br>
✅ <a href="https://tutanota.com/"><b>Tutanota</b></a> - is the world's most secure email service and amazingly easy to use.<br>
✅ <a href="https://protonmail.com/"><b>Protonmail</b></a> - is the world's largest secure email service, developed by CERN and MIT scientists.<br>
✅ <a href="https://www.startmail.com/en/"><b>Startmail</b></a> - private & encrypted email made easy.<br>
</p>

#####   Crypto


✅ <a href="https://keybase.io/"><b>Keybase</b></a> - it's open source and powered by public-key cryptography.<br>
</p>

#####   PGP Keyservers


✅ <a href="https://keyserver.ubuntu.com/"><b>SKS OpenPGP Key server</b></a> - services for the SKS keyservers used by OpenPGP.<br>
</p>

#### Systems/Services [<sup>[TOC]</sup>](#anger-table-of-contents)

#####   Operating Systems


✅ <a href="http://www.slackware.com/"><b>Slackware</b></a> - the most "Unix-like" Linux distribution.<br>
✅ <a href="https://www.openbsd.org/"><b>OpenBSD</b></a> - multi-platform 4.4BSD-based UNIX-like operating system.<br>
✅ <a href="https://hardenedbsd.org/"><b>HardenedBSD</b></a> - HardenedBSD aims to implement innovative exploit mitigation and security solutions.<br>
✅ <a href="https://www.kali.org/"><b>Kali Linux</b></a> - Linux distribution used for Penetration Testing, Ethical Hacking and network security assessments.<br>
✅ <a href="https://www.parrotsec.org/"><b>Parrot Security OS</b></a> - cyber security GNU/Linux environment.<br>
✅ <a href="https://www.backbox.org/"><b>Backbox Linux</b></a> - penetration test and security assessment oriented Ubuntu-based Linux distribution.<br>
✅ <a href="https://blackarch.org/"><b>BlackArch</b></a> - is an Arch Linux-based penetration testing distribution for penetration testers.<br>
✅ <a href="https://www.pentoo.ch/"><b>Pentoo</b></a> - is a security-focused livecd based on Gentoo.<br>
✅ <a href="https://securityonion.net/"><b>Security Onion</b></a> - Linux distro for intrusion detection, enterprise security monitoring, and log management.<br>
✅ <a href="https://tails.boum.org/"><b>Tails</b></a> - is a live system that aims to preserve your privacy and anonymity.<br>
✅ <a href="https://github.com/vedetta-com/vedetta"><b>vedetta</b></a> - OpenBSD router boilerplate.<br>
✅ <a href="https://www.qubes-os.org"><b>Qubes OS</b></a> - is a security-oriented OS that uses Xen-based virtualization.<br>
</p>

#####   HTTP(s) Services


✅ <a href="https://varnish-cache.org/"><b>Varnish Cache</b></a> - HTTP accelerator designed for content-heavy dynamic web sites.<br>
✅ <a href="https://nginx.org/"><b>Nginx</b></a> - open source web and reverse proxy server that is similar to Apache, but very light weight.<br>
✅ <a href="https://openresty.org/en/"><b>OpenResty</b></a> - is a dynamic web platform based on NGINX and LuaJIT.<br>
✅ <a href="https://github.com/alibaba/tengine"><b>Tengine</b></a> - a distribution of Nginx with some advanced features.<br>
✅ <a href="https://caddyserver.com/"><b>Caddy Server</b></a> - is an open source, HTTP/2-enabled web server with HTTPS by default.<br>
✅ <a href="https://www.haproxy.org/"><b>HAProxy</b></a> - the reliable, high performance TCP/HTTP load balancer.<br>
</p>

#####   DNS Services


✅ <a href="https://nlnetlabs.nl/projects/unbound/about/"><b>Unbound</b></a> - validating, recursive, and caching DNS resolver (with TLS).<br>
✅ <a href="https://www.knot-resolver.cz/"><b>Knot Resolver</b></a> - caching full resolver implementation, including both a resolver library and a daemon.<br>
✅ <a href="https://www.powerdns.com/"><b>PowerDNS</b></a> - is an open source authoritative DNS server, written in C++ and licensed under the GPL.<br>
</p>

#####   Other Services


✅ <a href="https://github.com/z3APA3A/3proxy"><b>3proxy</b></a> - tiny free proxy server.<br>
</p>

#####   Security/hardening


✅ <a href="https://twitter.com/EmeraldOnion"><b>Emerald Onion</b></a> - is a 501(c)(3) nonprofit organization and transit internet service provider (ISP).<br>
✅ <a href="https://github.com/pi-hole/pi-hole"><b>pi-hole</b></a> - the Pi-hole® is a DNS sinkhole that protects your devices from unwanted content.<br>
✅ <a href="https://github.com/stamparm/maltrail"><b>maltrail</b></a> - malicious traffic detection system.<br>
✅ <a href="https://github.com/Netflix/security_monkey"><b>security_monkey</b></a> - monitors AWS, GCP, OpenStack, and GitHub orgs for assets and their changes over time.<br>
✅ <a href="https://github.com/firecracker-microvm/firecracker"><b>firecracker</b></a> - secure and fast microVMs for serverless computing.<br>
✅ <a href="https://github.com/StreisandEffect/streisand"><b>streisand</b></a> - sets up a new server running your choice of WireGuard, OpenSSH, OpenVPN, and more.<br>
</p>

#### Networks [<sup>[TOC]</sup>](#anger-table-of-contents)

#####   Tools


✅ <a href="https://www.capanalysis.net/ca/"><b>CapAnalysis</b></a> - web visual tool to analyze large amounts of captured network traffic (PCAP analyzer).<br>
✅ <a href="https://github.com/digitalocean/netbox"><b>netbox</b></a> - IP address management (IPAM) and data center infrastructure management (DCIM) tool.<br>
</p>

#####   Labs


✅ <a href="https://labs.networkreliability.engineering/"><b>NRE Labs</b></a> - learn automation by doing it. Right now, right here, in your browser.<br>
</p>

#####   Other


✅ <a href="https://ee.lbl.gov/"><b>LBNL's Network Research Group</b></a> - home page of the Network Research Group (NRG).<br>
</p>

#### Containers/Orchestration [<sup>[TOC]</sup>](#anger-table-of-contents)

#####   CLI Tools


✅ <a href="https://github.com/google/gvisor"><b>gvisor</b></a> - container runtime sandbox.<br>
✅ <a href="https://github.com/bcicen/ctop"><b>ctop</b></a> - top-like interface for container metrics.<br>
</p>

#####   Web Tools


✅ <a href="https://github.com/moby/moby"><b>Moby</b></a> - a collaborative project for the container ecosystem to assemble container-based system.<br>
✅ <a href="https://traefik.io/"><b>Traefik</b></a> - open source reverse proxy/load balancer provides easier integration with Docker and Let's encrypt.<br>
✅ <a href="https://github.com/Kong/kong"><b>kong</b></a> - The Cloud-Native API Gateway.<br>
✅ <a href="https://github.com/rancher/rancher"><b>rancher</b></a> - complete container management platform.<br>
✅ <a href="https://github.com/portainer/portainer"><b>portainer</b></a> - making Docker management easy.<br>
✅ <a href="https://github.com/jwilder/nginx-proxy"><b>nginx-proxy</b></a> - automated nginx proxy for Docker containers using docker-gen.<br>
</p>

#####   Security


✅ <a href="https://github.com/docker/docker-bench-security"><b>docker-bench-security</b></a> - checks for dozens of common best-practices around deploying Docker.<br>
✅ <a href="https://github.com/aquasecurity/trivy"><b>trivy</b></a> - vulnerability scanner for containers, suitable for CI.<br>
✅ <a href="https://goharbor.io/"><b>Harbor</b></a> - cloud native registry project that stores, signs, and scans content.<br>
</p>

#####   Manuals/Tutorials/Best Practices


✅ <a href="https://github.com/wsargent/docker-cheat-sheet"><b>docker-cheat-sheet</b></a> - a quick reference cheat sheet on Docker.<br>
✅ <a href="https://github.com/veggiemonk/awesome-docker"><b>awesome-docker</b></a> - a curated list of Docker resources and projects.<br>
✅ <a href="https://github.com/yeasy/docker_practice"><b>docker_practice</b></a> - learn and understand Docker technologies, with real DevOps practice!<br>
✅ <a href="https://github.com/docker/labs"><b>labs
</b></a> - is a collection of tutorials for learning how to use Docker with various tools.<br>
✅ <a href="https://github.com/jessfraz/dockerfiles"><b>dockerfiles</b></a> - various Dockerfiles I use on the desktop and on servers.<br>
✅ <a href="https://github.com/kelseyhightower/kubernetes-the-hard-way"><b>kubernetes-the-hard-way</b></a> - bootstrap Kubernetes the hard way on Google Cloud Platform. No scripts.<br>
✅ <a href="https://github.com/jamesward/kubernetes-the-easy-way"><b>kubernetes-the-easy-way</b></a> - bootstrap Kubernetes the easy way on Google Cloud Platform. No scripts.<br>
✅ <a href="https://github.com/dennyzhang/cheatsheet-kubernetes-A4"><b>cheatsheet-kubernetes-A4</b></a> - Kubernetes CheatSheets in A4.<br>
✅ <a href="https://github.com/kabachook/k8s-security"><b>k8s-security</b></a> - kubernetes security notes and best practices.<br>
✅ <a href="https://learnk8s.io/production-best-practices/"><b>kubernetes-production-best-practices</b></a> - checklists with best-practices for production-ready Kubernetes.<br>
✅ <a href="https://github.com/freach/kubernetes-security-best-practice"><b>kubernetes-production-best-practices</b></a> - kubernetes security - best practice guide.<br>
✅ <a href="https://github.com/hjacobs/kubernetes-failure-stories"><b>kubernetes-failure-stories</b></a> - is a compilation of public failure/horror stories related to Kubernetes.<br>
</p>

#### Manuals/Howtos/Tutorials [<sup>[TOC]</sup>](#anger-table-of-contents)

#####   Shell/Command line


✅ <a href="https://github.com/dylanaraps/pure-bash-bible"><b>pure-bash-bible</b></a> - is a collection of pure bash alternatives to external processes.<br>
✅ <a href="https://github.com/dylanaraps/pure-sh-bible"><b>pure-sh-bible</b></a> - is a collection of pure POSIX sh alternatives to external processes.<br>
✅ <a href="https://github.com/Idnan/bash-guide"><b>bash-guide</b></a> - is a guide to learn bash.<br>
✅ <a href="https://github.com/denysdovhan/bash-handbook"><b>bash-handbook</b></a> - for those who wanna learn Bash.<br>
✅ <a href="https://wiki.bash-hackers.org/start"><b>The Bash Hackers Wiki</b></a> - hold documentation of any kind about GNU Bash.<br>
✅ <a href="http://pubs.opengroup.org/onlinepubs/9699919799/utilities/contents.html"><b>Shell & Utilities</b></a> - describes the commands offered to application programs by POSIX-conformant systems.<br>
✅ <a href="https://github.com/jlevy/the-art-of-command-line"><b>the-art-of-command-line</b></a> - master the command line, in one page.<br>
✅ <a href="https://google.github.io/styleguide/shellguide.html"><b>Shell Style Guide</b></a> - a shell style guide for Google-originated open-source projects.<br>
</p>

#####   Text Editors


✅ <a href="https://vim.rtorr.com/"><b>Vim Cheat Sheet</b></a> - great multi language vim guide.<br>
</p>

#####   Python


✅ <a href="https://awesome-python.com/"><b>Awesome Python</b></a> - a curated list of awesome Python frameworks, libraries, software and resources.<br>
✅ <a href="https://github.com/gto76/python-cheatsheet"><b>python-cheatsheet</b></a> - comprehensive Python cheatsheet.<br>
✅ <a href="https://www.pythoncheatsheet.org/"><b>pythoncheatsheet.org</b></a> - basic reference for beginner and advanced developers.<br>
</p>

#####   Sed & Awk & Other


✅ <a href="https://posts.specterops.io/fawk-yeah-advanced-sed-and-awk-usage-parsing-for-pentesters-3-e5727e11a8ad?gi=c8f9506b26b6"><b>F’Awk Yeah!</b></a> - advanced sed and awk usage (Parsing for Pentesters 3).<br>
</p>

#####   \*nix & Network


✅ <a href="https://www.cyberciti.biz/"><b>nixCraft</b></a> - linux and unix tutorials for new and seasoned sysadmin.<br>
✅ <a href="https://www.tecmint.com/"><b>TecMint</b></a> - the ideal Linux blog for Sysadmins & Geeks.<br>
✅ <a href="http://www.omnisecu.com/index.php"><b>Omnisecu</b></a> - free Networking, System Administration and Security tutorials.<br>
✅ <a href="https://github.com/cirosantilli/linux-cheat"><b>linux-cheat</b></a> - Linux tutorials and cheatsheets. Minimal examples. Mostly user-land CLI utilities.<br>
✅ <a href="https://github.com/snori74/linuxupskillchallenge"><b>linuxupskillchallenge</b></a> - learn the skills required to sysadmin.<br>
✅ <a href="http://cb.vu/unixtoolbox.xhtml"><b>Unix Toolbox</b></a> - Unix/Linux/BSD commands and tasks which are useful for IT work or for advanced users.<br>
✅ <a href="https://linux-kernel-labs.github.io/refs/heads/master/index.html"><b>Linux Kernel Teaching</b></a> - is a collection of lectures and labs Linux kernel topics.<br>
✅ <a href="https://peteris.rocks/blog/htop/"><b>htop explained</b></a> - explanation of everything you can see in htop/top on Linux.<br>
✅ <a href="https://linuxguideandhints.com/"><b>Linux Guide and Hints</b></a> - tutorials on system administration in Fedora and CentOS.<br>
✅ <a href="https://github.com/NanXiao/strace-little-book"><b>strace-little-book</b></a> - a little book which introduces strace.<br>
✅ <a href="https://github.com/goldshtn/linux-tracing-workshop"><b>linux-tracing-workshop</b></a> - examples and hands-on labs for Linux tracing tools workshops.<br>
✅ <a href="https://github.com/bagder/http2-explained"><b>http2-explained</b></a> - a detailed document explaining and documenting HTTP/2.<br>
✅ <a href="https://github.com/bagder/http3-explained"><b>http3-explained</b></a> - a document describing the HTTP/3 and QUIC protocols.<br>
✅ <a href="https://www.manning.com/books/http2-in-action"><b>HTTP/2 in Action</b></a> - an excellent introduction to the new HTTP/2 standard.<br>
✅ <a href="https://www.saminiir.com/lets-code-tcp-ip-stack-1-ethernet-arp/"><b>Let's code a TCP/IP stack</b></a> - great stuff to learn network and system programming at a deeper level.<br>
✅ <a href="https://github.com/trimstray/nginx-admins-handbook"><b>Nginx Admin's Handbook</b></a> - how to improve NGINX performance, security and other important things.<br>
✅ <a href="https://github.com/digitalocean/nginxconfig.io"><b>nginxconfig.io</b></a> - NGINX config generator on steroids.<br>
✅ <a href="https://infosec.mozilla.org/guidelines/openssh"><b>openssh guideline</b></a> - is to help operational teams with the configuration of OpenSSH server and client.<br>
✅ <a href="https://gravitational.com/blog/ssh-handshake-explained/"><b>SSH Handshake Explained</b></a> - is a relatively brief description of the SSH handshake.<br>
✅ <a href="https://kb.isc.org/docs/using-this-knowledgebase"><b>ISC's Knowledgebase</b></a> - you'll find some general information about BIND 9, ISC DHCP, and Kea DHCP.<br>
✅ <a href="https://packetlife.net/"><b>PacketLife.net</b></a> - a place to record notes while studying for Cisco's CCNP certification.<br>
</p>

#####   Microsoft


✅ <a href="https://github.com/infosecn1nja/AD-Attack-Defense"><b>AD-Attack-Defense</b></a> - attack and defend active directory using modern post exploitation activity.<br>
</p>

#####   Large-scale systems


✅ <a href="https://github.com/donnemartin/system-design-primer"><b>The System Design Primer</b></a> - learn how to design large-scale systems.<br>
✅ <a href="https://github.com/binhnguyennus/awesome-scalability"><b>Awesome Scalability</b></a> - best practices in building High Scalability, High Availability, High Stability, and more.<br>
✅ <a href="https://engineering.videoblocks.com/web-architecture-101-a3224e126947?gi=a896808d22a"><b>Web Architecture 101</b></a> - the basic architecture concepts.<br>
</p>

#####   System hardening


✅ <a href="https://www.cisecurity.org/cis-benchmarks/"><b>CIS Benchmarks</b></a> - secure configuration settings for over 100 technologies, available as a free PDF.<br>
✅ <a href="https://highon.coffee/blog/security-harden-centos-7/"><b>Security Harden CentOS 7</b></a> - this walks you through the steps required to security harden CentOS.<br>
✅ <a href="https://www.lisenet.com/2017/centos-7-server-hardening-guide/"><b>CentOS 7 Server Hardening Guide</b></a> - great guide for hardening CentOS; familiar with OpenSCAP.<br>
✅ <a href="https://github.com/decalage2/awesome-security-hardening"><b>awesome-security-hardening</b></a> - is a collection of security hardening guides, tools and other resources.<br>
✅ <a href="https://github.com/trimstray/the-practical-linux-hardening-guide"><b>The Practical Linux Hardening Guide</b></a> - provides a high-level overview of hardening GNU/Linux systems.<br>
✅ <a href="https://madaidans-insecurities.github.io/guides/linux-hardening.html"><b>Linux Hardening Guide</b></a> - how to harden Linux as much as possible for security and privacy.<br>
</p>

#####   Security & Privacy


✅ <a href="https://www.hackingarticles.in/"><b>Hacking Articles</b></a> - LRaj Chandel's Security & Hacking Blog.<br>
✅ <a href="https://github.com/toniblyx/my-arsenal-of-aws-security-tools"><b>AWS security tools</b></a> - make your AWS cloud environment more secure.<br>
✅ <a href="https://inventory.rawsec.ml/index.html"><b>Rawsec's CyberSecurity Inventory</b></a> - an inventory of tools and resources about CyberSecurity.<br>
✅ <a href="https://tls.ulfheim.net/"><b>The Illustrated TLS Connection</b></a> - every byte of a TLS connection explained and reproduced.<br>
✅ <a href="https://github.com/ssllabs/research/wiki/SSL-and-TLS-Deployment-Best-Practices"><b>SSL Research</b></a> - SSL and TLS Deployment Best Practices by SSL Labs.<br>
✅ <a href="http://selinuxgame.org/index.html"><b>SELinux Game</b></a> - learn SELinux by doing. Solve Puzzles, show skillz.<br>
✅ <a href="https://smallstep.com/blog/everything-pki.html"><b>Certificates and PKI</b></a> - everything you should know about certificates and PKI but are too afraid to ask.<br>
✅ <a href="https://appsecco.com/books/subdomain-enumeration/"><b>The Art of Subdomain Enumeration</b></a> - a reference for subdomain enumeration techniques.<br>
✅ <a href="https://lifehacker.com/the-comprehensive-guide-to-quitting-google-1830001964"><b>Quitting Google</b></a> - the comprehensive guide to quitting Google.<br>
</p>

#####   Web Apps


✅ <a href="https://www.owasp.org/index.php/Main_Page"><b>OWASP</b></a> - worldwide not-for-profit charitable organization focused on improving the security of software.<br>
✅ <a href="https://www.owasp.org/index.php/Category:OWASP_Application_Security_Verification_Standard_Project"><b>OWASP ASVS 3.0.1</b></a> - OWASP Application Security Verification Standard Project.<br>
✅ <a href="https://github.com/Santandersecurityresearch/asvs"><b>OWASP ASVS 3.0.1 Web App</b></a> - simple web app that helps developers understand the ASVS requirements.<br>
✅ <a href="https://github.com/OWASP/ASVS/tree/master/4.0"><b>OWASP ASVS 4.0</b></a> - is a list of application security requirements or tests.<br>
✅ <a href="https://www.owasp.org/index.php/OWASP_Testing_Project"><b>OWASP Testing Guide v4</b></a> - includes a "best practice" penetration testing framework.<br>
✅ <a href="https://github.com/OWASP/DevGuide"><b>OWASP Dev Guide</b></a> - this is the development version of the OWASP Developer Guide.<br>
✅ <a href="https://github.com/OWASP/wstg"><b>OWASP WSTG</b></a> - is a comprehensive open source guide to testing the security of web apps.<br>
✅ <a href="https://www.owasp.org/index.php/OWASP_API_Security_Project"><b>OWASP API Security Project</b></a> - focuses specifically on the top ten vulnerabilities in API security.<br>
✅ <a href="https://infosec.mozilla.org/guidelines/web_security.html"><b>Mozilla Web Security</b></a> - help operational teams with creating secure web applications.<br>
✅ <a href="https://github.com/Netflix/security-bulletins"><b>security-bulletins</b></a> - security bulletins that relate to Netflix Open Source.<br>
✅ <a href="https://github.com/shieldfy/API-Security-Checklist"><b>API-Security-Checklist</b></a> - security countermeasures when designing, testing, and releasing your API.<br>
✅ <a href="https://enable-cors.org/index.html"><b>Enable CORS</b></a> - enable cross-origin resource sharing.<br>
✅ <a href="https://appsecwiki.com/#/"><b>Application Security Wiki</b></a> - is an initiative to provide all application security related resources at one place.<br>
✅ <a href="https://github.com/GrrrDog/weird_proxies/wiki"><b>Weird Proxies</b></a> - reverse proxy related attacks; it is a result of analysis of various proxies.<br>
✅ <a href="https://dfir.it/blog/2015/08/12/webshell-every-time-the-same-purpose/"><b>Webshells</b></a> - great series about malicious payloads.<br>
✅ <a href="https://portswigger.net/blog/practical-web-cache-poisoning"><b>Practical Web Cache Poisoning</b></a> - show you how to compromise websites by using esoteric web features.<br>
✅ <a href="https://github.com/bl4de/research/tree/master/hidden_directories_leaks"><b>Hidden directories and files</b></a> - as a source of sensitive information about web application.<br>
✅ <a href="https://bo0om.ru/en/"><b>Explosive blog</b></a> - great blog about cybersec and pentests.<br>
✅ <a href="https://www.netsparker.com/security-cookies-whitepaper/"><b>Security Cookies</b></a> - this paper will take a close look at cookie security.<br>
✅ <a href="https://github.com/GitGuardian/APISecurityBestPractices"><b>APISecurityBestPractices</b></a> - help you keep secrets (API keys, db credentials, certificates) out of source code.<br>
</p>

#####   All-in-one


✅ <a href="https://lzone.de/cheat-sheet/"><b>LZone Cheat Sheets</b></a> - all cheat sheets.<br>
✅ <a href="https://github.com/rstacruz/cheatsheets"><b>Dan’s Cheat Sheets’s</b></a> - massive cheat sheets documentation.<br>
✅ <a href="https://devhints.io/"><b>Rico's cheatsheets</b></a> - this is a modest collection of cheatsheets.<br>
✅ <a href="https://devdocs.io/"><b>DevDocs API</b></a> - combines multiple API documentations in a fast, organized, and searchable interface.<br>
✅ <a href="https://cheat.sh/"><b>cheat.sh</b></a> - the only cheat sheet you need.<br>
✅ <a href="https://gnulinux.guru/"><b>gnulinux.guru</b></a> - collection of cheat sheets about bash, vim and networking.<br>
</p>

#####   Ebooks


✅ <a href="https://github.com/EbookFoundation/free-programming-books"><b>free-programming-books</b></a> - list of free learning resources in many languages.<br>
</p>

#####   Other


✅ <a href="https://bitvijays.github.io/LFC-VulnerableMachines.html"><b>CTF Series : Vulnerable Machines</b></a> - the steps below could be followed to find vulnerabilities and exploits.<br>
✅ <a href="https://github.com/manoelt/50M_CTF_Writeup"><b>50M_CTF_Writeup</b></a> - $50 million CTF from Hackerone - writeup.<br>
✅ <a href="https://github.com/j00ru/ctf-tasks"><b>ctf-tasks</b></a> - an archive of low-level CTF challenges developed over the years.<br>
✅ <a href="https://hshrzd.wordpress.com/how-to-start/"><b>How to start RE/malware analysis?</b></a> - collection of some hints and useful links for the beginners.<br>
✅ <a href="http://www.kegel.com/c10k.html"><b>The C10K problem</b></a> - it's time for web servers to handle ten thousand clients simultaneously, don't you think?<br>
✅ <a href="https://blog.benjojo.co.uk/post/why-is-ethernet-mtu-1500"><b>How 1500 bytes became the MTU of the internet</b></a> - great story about the Maximum Transmission Unit.<br>
✅ <a href="http://poormansprofiler.org/"><b>poor man's profiler</b></a> - like dtrace's don't really provide methods to see what programs are blocking on.<br>
✅ <a href="https://nickcraver.com/blog/2017/05/22/https-on-stack-overflow/"><b>HTTPS on Stack Overflow</b></a> - this is the story of a long journey regarding the implementation of SSL.<br>
✅ <a href="https://drawings.jvns.ca/"><b>Julia's Drawings</b></a> - some drawings about programming and unix world, zines about systems & debugging tools.<br>
✅ <a href="https://github.com/corkami/collisions"><b>Hash collisions</b></a> - this great repository is focused on hash collisions exploitation.<br>
✅ <a href="https://github.com/in3rsha/sha256-animation"><b>sha256-animation</b></a> - animation of the SHA-256 hash function in your terminal.<br>
✅ <a href="https://labs.ripe.net/Members/cteusche/bgp-meets-cat"><b>BGP Meets Cat</b></a> - after 3072 hours of manipulating BGP, Job Snijders has succeeded in drawing a Nyancat.<br>
✅ <a href="https://github.com/benjojo/bgp-battleships"><b>bgp-battleships</b></a> - playing battleships over BGP.<br>
✅ <a href="https://github.com/alex/what-happens-when"><b>What happens when...</b></a> - you type google.com into your browser and press enter?<br>
✅ <a href="https://github.com/vasanthk/how-web-works"><b>how-web-works</b></a> - based on the 'What happens when...' repository.<br>
✅ <a href="https://robertheaton.com/2018/11/28/https-in-the-real-world/"><b>HTTPS in the real world</b></a> - great tutorial explain how HTTPS works in the real world.<br>
✅ <a href="https://about.gitlab.com/2018/11/14/how-we-spent-two-weeks-hunting-an-nfs-bug/"><b>Gitlab and NFS bug</b></a> - how we spent two weeks hunting an NFS bug in the Linux kernel.<br>
✅ <a href="https://about.gitlab.com/2017/02/10/postmortem-of-database-outage-of-january-31/"><b>Gitlab melts down</b></a> - postmortem on the database outage of January 31 2017 with the lessons we learned.<br>
✅ <a href="http://www.catb.org/esr/faqs/hacker-howto.html"><b>How To Become A Hacker</b></a> - if you want to be a hacker, keep reading.<br>
✅ <a href="http://ithare.com/infographics-operation-costs-in-cpu-clock-cycles/"><b>Operation Costs in CPU</b></a> - should help to estimate costs of certain operations in CPU clocks.<br>
✅ <a href="https://cstack.github.io/db_tutorial/"><b>Let's Build a Simple Database</b></a> - writing a sqlite clone from scratch in C.<br>
✅ <a href="https://djhworld.github.io/post/2019/05/21/i-dont-know-how-cpus-work-so-i-simulated-one-in-code/"><b>simple-computer</b></a> - great resource to understand how computers work under the hood.<br>
✅ <a href="https://www.troyhunt.com/working-with-154-million-records-on/"><b>The story of "Have I been pwned?"</b></a> - working with 154 million records on Azure Table Storage.<br>
✅ <a href="https://www.top500.org/"><b>TOP500 Supercomputers</b></a> - shows the 500 most powerful commercially available computer systems known to us.<br>
✅ <a href="https://www.shellntel.com/blog/2017/2/8/how-to-build-a-8-gpu-password-cracker"><b>How to build a 8 GPU password cracker</b></a> - any "black magic" or hours of frustration like desktop components do.<br>
✅ <a href="https://home.cern/science/computing"><b>CERN Data Centre</b></a> - 3D visualizations of the CERN computing environments (and more).<br>
✅ <a href="http://howfuckedismydatabase.com/"><b>How fucked is my database</b></a> - evaluate how fucked your database is with this handy website.<br>
✅ <a href="https://krisbuytaert.be/blog/linux-troubleshooting-101-2016-edition/index.html"><b>Linux Troubleshooting 101 , 2016 Edition</b></a> - everything is a DNS Problem...<br>
✅ <a href="https://open.buffer.com/5-whys-process/"><b>Five Whys</b></a> - you know what the problem is, but you cannot solve it?<br>
✅ <a href="https://gvnshtn.com/maersk-me-notpetya/"><b>Maersk, me & notPetya</b></a> - how did ransomware successfully hijack hundreds of domain controllers?<br>
✅ <a href="https://howhttps.works/"><b>howhttps.works</b></a> - how HTTPS works ...in a comic!<br>
✅ <a href="https://howdns.works/"><b>howdns.works</b></a> - a fun and colorful explanation of how DNS works.<br>
✅ <a href="https://postgresqlco.nf/en/doc/param/"><b>POSTGRESQLCO.NF</b></a> - your postgresql.conf documentation and recommendations.<br>
</p>

#### Inspiring Lists [<sup>[TOC]</sup>](#anger-table-of-contents)

#####   SysOps/DevOps


✅ <a href="https://github.com/kahun/awesome-sysadmin"><b>Awesome Sysadmin</b></a> - amazingly awesome open source sysadmin resources.<br>
✅ <a href="https://github.com/alebcay/awesome-shell"><b>Awesome Shell</b></a> - awesome command-line frameworks, toolkits, guides and gizmos.<br>
✅ <a href="https://github.com/learnbyexample/Command-line-text-processing"><b>Command-line-text-processing</b></a> - finding text to search and replace, sorting to beautifying, and more.<br>
✅ <a href="https://github.com/caesar0301/awesome-pcaptools"><b>Awesome Pcaptools</b></a> - collection of tools developed by other researchers to process network traces.<br>
✅ <a href="https://github.com/zoidbergwill/awesome-ebpf"><b>awesome-ebpf</b></a> - a curated list of awesome projects related to eBPF.<br>
✅ <a href="https://github.com/leandromoreira/linux-network-performance-parameters"><b>Linux Network Performance</b></a> - where some of the network sysctl variables fit into the Linux/Kernel network flow.<br>
✅ <a href="https://github.com/dhamaniasad/awesome-postgres"><b>Awesome Postgres</b></a> - list of awesome PostgreSQL software, libraries, tools and resources.<br>
✅ <a href="https://github.com/enochtangg/quick-SQL-cheatsheet"><b>quick-SQL-cheatsheet</b></a> - a quick reminder of all SQL queries and examples on how to use them.<br>
✅ <a href="https://github.com/Kickball/awesome-selfhosted"><b>Awesome-Selfhosted</b></a> - list of Free Software network services and web applications which can be hosted locally.<br>
✅ <a href="https://wiki.archlinux.org/index.php/List_of_applications"><b>List of applications</b></a> - huge list of apps sorted by category, as a reference for those looking for packages.<br>
✅ <a href="https://github.com/InterviewMap/CS-Interview-Knowledge-Map"><b>CS-Interview-Knowledge-Map</b></a> - build the best interview map.<br>
✅ <a href="https://github.com/Tikam02/DevOps-Guide"><b>DevOps-Guide</b></a> - DevOps Guide from basic to advanced with Interview Questions and Notes.<br>
✅ <a href="https://issue.freebsdfoundation.org/publication/?m=33057&l=1&view=issuelistBrowser"><b>FreeBSD Journal</b></a> - it is a great list of periodical magazines about FreeBSD and other important things.<br>
✅ <a href="https://github.com/bregman-arie/devops-interview-questions"><b>devops-interview-questions</b></a> - contains interview questions on various DevOps and SRE related topics.<br></p>

#####   Developers


✅ <a href="https://github.com/kamranahmedse/developer-roadmap"><b>Web Developer Roadmap</b></a> - roadmaps, articles and resources to help you choose your path, learn and improve.<br>
✅ <a href="https://github.com/thedaviddias/Front-End-Checklist"><b>Front-End-Checklist</b></a> - the perfect Front-End Checklist for modern websites and meticulous developers.<br>
✅ <a href="https://github.com/thedaviddias/Front-End-Performance-Checklist"><b>Front-End-Performance-Checklist</b></a> - Front-End Performance Checklist that runs faster than the others.<br>
✅ <a href="https://rszalski.github.io/magicmethods/"><b>Python's Magic Methods</b></a> - what are magic methods? They're everything in object-oriented Python.<br>
✅ <a href="https://github.com/satwikkansal/wtfpython"><b>wtfpython</b></a> - a collection of surprising Python snippets and lesser-known features.<br>
✅ <a href="https://github.com/twhite96/js-dev-reads"><b>js-dev-reads</b></a> - a list of books and articles for the discerning web developer to read.<br>
✅ <a href="https://github.com/RomuloOliveira/commit-messages-guide"><b>Commit messages guide</b></a> - a guide to understand the importance of commit messages.<br>
</p>

#####   Security/Pentesting


✅ <a href="https://github.com/qazbnm456/awesome-web-security"><b>Awesome Web Security</b></a> - a curated list of Web Security materials and resources.<br>
✅ <a href="https://github.com/joe-shenouda/awesome-cyber-skills"><b>awesome-cyber-skills</b></a> - a curated list of hacking environments where you can train your cyber skills.<br>
✅ <a href="https://github.com/devsecops/awesome-devsecops"><b>awesome-devsecops</b></a> - an authoritative list of awesome devsecops tools.<br>
✅ <a href="https://github.com/jivoi/awesome-osint"><b>awesome-osint</b></a> - is a curated list of amazingly awesome OSINT.<br>
✅ <a href="https://github.com/HolyBugx/HolyTips"><b>HolyTips</b></a> - tips and tutorials on Bug Bounty Hunting and Web App Security.<br>
✅ <a href="https://github.com/hslatman/awesome-threat-intelligence"><b>awesome-threat-intelligence</b></a> - a curated list of Awesome Threat Intelligence resources.<br>
✅ <a href="https://github.com/infosecn1nja/Red-Teaming-Toolkit"><b>Red-Teaming-Toolkit</b></a> - a collection of open source and commercial tools that aid in red team operations.<br>
✅ <a href="https://github.com/snoopysecurity/awesome-burp-extensions"><b>awesome-burp-extensions</b></a> - a curated list of amazingly awesome Burp Extensions.<br>
✅ <a href="https://github.com/Hack-with-Github/Free-Security-eBooks"><b>Free Security eBooks</b></a> - list of a Free Security and Hacking eBooks.<br>
✅ <a href="https://github.com/yeahhub/Hacking-Security-Ebooks"><b>Hacking-Security-Ebooks</b></a> - top 100 Hacking & Security E-Books.<br>
✅ <a href="https://github.com/nikitavoloboev/privacy-respecting"><b>privacy-respecting</b></a> - curated list of privacy respecting services and software.<br>
✅ <a href="https://github.com/wtsxDev/reverse-engineering"><b>reverse-engineering</b></a> - list of awesome reverse engineering resources.<br>
✅ <a href="https://github.com/michalmalik/linux-re-101"><b>linux-re-101</b></a> - a collection of resources for linux reverse engineering.<br>
✅ <a href="https://github.com/onethawt/reverseengineering-reading-list"><b>reverseengineering-reading-list</b></a> - a list of Reverse Engineering articles, books, and papers.<br>
✅ <a href="https://github.com/0xInfection/Awesome-WAF"><b>Awesome-WAF</b></a> - a curated list of awesome web-app firewall (WAF) stuff.<br>
✅ <a href="https://github.com/jakejarvis/awesome-shodan-queries"><b>awesome-shodan-queries</b></a> - interesting, funny, and depressing search queries to plug into shodan.io.<br>
✅ <a href="https://github.com/danielmiessler/RobotsDisallowed"><b>RobotsDisallowed</b></a> - a curated list of the most common and most interesting robots.txt disallowed directories.<br>
✅ <a href="https://github.com/Kayzaks/HackingNeuralNetworks"><b>HackingNeuralNetworks</b></a> - is a small course on exploiting and defending neural networks.<br>
✅ <a href="https://gist.github.com/joepie91/7e5cad8c0726fd6a5e90360a754fc568"><b>wildcard-certificates</b></a> - why you probably shouldn't use a wildcard certificate.<br>
✅ <a href="https://gist.github.com/joepie91/5a9909939e6ce7d09e29"><b>Don't use VPN services</b></a> -  which is what every third-party "VPN provider" does.<br>
✅ <a href="https://github.com/InQuest/awesome-yara"><b>awesome-yara</b></a> - a curated list of awesome YARA rules, tools, and people.<br>
✅ <a href="https://github.com/drduh/macOS-Security-and-Privacy-Guide"><b>macOS-Security-and-Privacy-Guide</b></a> - guide to securing and improving privacy on macOS.<br>
✅ <a href="https://github.com/usnistgov/macos_security"><b>macos_security</b></a> - macOS Security Compliance Project.<br>
✅ <a href="https://github.com/PaulSec/awesome-sec-talks"><b>awesome-sec-talks</b></a> - is a collected list of awesome security talks.<br>
✅ <a href="https://github.com/k4m4/movies-for-hackers"><b>Movies for Hackers</b></a> - list of movies every hacker & cyberpunk must watch.<br>
✅ <a href="https://github.com/danieldizzy/Cryptography_1"><b>Cryptography_1</b></a> - materials used whilst taking Prof. Dan Boneh Stanford Crypto course.<br>
✅ <a href="https://github.com/ashutosh1206/Crypton"><b>Crypton</b></a> - library to learn and practice Offensive and Defensive Cryptography.<br>
</p>

#####   Other


✅ <a href="https://www.cheatography.com/"><b>Cheatography</b></a> - over 3,000 free cheat sheets, revision aids and quick references.<br>
✅ <a href="https://github.com/mre/awesome-static-analysis"><b>awesome-static-analysis</b></a> - static analysis tools for all programming languages.<br>
✅ <a href="https://github.com/ossu/computer-science"><b>computer-science</b></a> - path to a free self-taught education in Computer Science.<br>
✅ <a href="https://github.com/danluu/post-mortems"><b>post-mortems</b></a> - is a collection of postmortems (config errors, hardware failures, and more).<br>
✅ <a href="https://github.com/danistefanovic/build-your-own-x"><b>build-your-own-x</b></a> - build your own (insert technology here).<br>
✅ <a href="https://github.com/rby90/Project-Based-Tutorials-in-C"><b>Project-Based-Tutorials-in-C</b></a> - is a curated list of project-based tutorials in C.<br>
✅ <a href="https://github.com/kylelobo/The-Documentation-Compendium"><b>The-Documentation-Compendium</b></a> - various README templates & tips on writing high-quality documentation.<br>
✅ <a href="https://github.com/mahmoud/awesome-python-applications"><b>awesome-python-applications</b></a> - free software that works great, and also happens to be open-source Python.<br>
✅ <a href="https://github.com/awesomedata/awesome-public-datasets"><b>awesome-public-datasets</b></a> - a topic-centric list of HQ open datasets.<br>
✅ <a href="https://github.com/Sahith02/machine-learning-algorithms"><b>machine-learning-algorithms</b></a> - a curated list of all machine learning algorithms and concepts.<br>
</p>

#### Blogs/Podcasts/Videos [<sup>[TOC]</sup>](#anger-table-of-contents)

#####   SysOps/DevOps


✅ <a href="https://www.youtube.com/watch?v=nAFpkV5-vuI"><b>Varnish for PHP developers</b></a> - very interesting presentation of Varnish by Mattias Geniar.<br>
✅ <a href="https://www.youtube.com/watch?v=CZ3wIuvmHeM"><b>A Netflix Guide to Microservices</b></a> - talks about the chaotic and vibrant world of microservices at Netflix.<br>
</p>

#####   Developers


✅ <a href="https://www.youtube.com/watch?v=yOyaJXpAYZQ"><b>Comparing C to machine lang</b></a> - compare a simple C app with the compiled machine code of that program.<br>
</p>

#####   Geeky Persons


✅ <a href="http://www.brendangregg.com/"><b>Brendan Gregg's Blog</b></a> - is an industry expert in computing performance and cloud computing.<br>
✅ <a href="https://gynvael.coldwind.pl/"><b>Gynvael "GynDream" Coldwind</b></a> - is a IT security engineer at Google.<br>
✅ <a href="http://lcamtuf.coredump.cx/"><b>Michał "lcamtuf" Zalewski</b></a> - white hat hacker, computer security expert.<br>
✅ <a href="https://ma.ttias.be/"><b>Mattias Geniar</b></a> - developer, sysadmin, blogger, podcaster and public speaker.<br>
✅ <a href="https://nickcraver.com/"><b>Nick Craver</b></a> - software developer and systems administrator for Stack Exchange.<br>
✅ <a href="https://scotthelme.co.uk/"><b>Scott Helme</b></a> - security researcher, speaker and founder of securityheaders.com and report-uri.com.<br>
✅ <a href="https://krebsonsecurity.com/"><b>Brian Krebs</b></a> - The Washington Post and now an Independent investigative journalist.<br>
✅ <a href="https://www.schneier.com/"><b>Bruce Schneier</b></a> - is an internationally renowned security technologist, called a "security guru".<br>
✅ <a href="https://chrissymorgan.co.uk/"><b>Chrissy Morgan</b></a> - advocate of practical learning, Chrissy also takes part in bug bounty programs.<br>
✅ <a href="https://blog.zsec.uk/"><b>Andy Gill</b></a> - is a hacker at heart who works as a senior penetration tester.<br>
✅ <a href="https://danielmiessler.com/"><b>Daniel Miessler</b></a> - cybersecurity expert and writer.<br>
✅ <a href="https://samy.pl/"><b>Samy Kamkar</b></a> -  is an American privacy and security researcher, computer hacker.<br>
✅ <a href="https://www.j4vv4d.com/"><b>Javvad Malik</b></a> - is a security advocate at AlienVault, a blogger event speaker and industry commentator.<br>
✅ <a href="https://www.grahamcluley.com/"><b>Graham Cluley</b></a> - public speaker and independent computer security analyst.<br>
✅ <a href="https://security.szurek.pl/"><b>Kacper Szurek</b></a> - detection engineer at ESET.<br>
✅ <a href="https://www.troyhunt.com/"><b>Troy Hunt</b></a> - web security expert known for public education and outreach on security topics.<br>
✅ <a href="https://raymii.org/s/index.html"><b>raymii.org</b></a> - sysadmin specializing in building high availability cloud environments.<br>
✅ <a href="https://robert.penz.name/"><b>Robert Penz</b></a> - IT security expert.<br>
</p>

#####   Geeky Blogs


✅ <a href="https://linux-audit.com/"><b>Linux Audit</b></a> - the Linux security blog about auditing, hardening and compliance by Michael Boelen.<br>
✅ <a href="https://linuxsecurity.expert/"><b>
Linux Security Expert</b></a> - trainings, howtos, checklists, security tools, and more.<br>
✅ <a href="http://www.grymoire.com/"><b>The Grymoire</b></a> - collection of useful incantations for wizards, be you computer wizards, magicians, or whatever.<br>
✅ <a href="https://www.secjuice.com"><b>Secjuice</b></a> - is the only non-profit, independent and volunteer led publication in the information security space.<br>
✅ <a href="https://duo.com/decipher"><b>Decipher</b></a> - security news that informs and inspires.<br>
</p>

#####   Geeky Vendor Blogs


✅ <a href="https://www.tenable.com/podcast"><b>Tenable Podcast</b></a> - conversations and interviews related to Cyber Exposure, and more.<br>
✅ <a href="https://nakedsecurity.sophos.com/"><b>Sophos</b></a> - threat news room, giving you news, opinion, advice and research on computer security issues.<br>
✅ <a href="https://www.tripwire.com/state-of-security/"><b>Tripwire State of Security</b></a> - blog featuring the latest news, trends and insights on current security issues.<br>
✅ <a href="https://blog.malwarebytes.com/"><b>Malwarebytes Labs Blog</b></a> - security blog aims to provide insider news about cybersecurity.<br>
✅ <a href="https://www.trustedsec.com/category/articles/"><b>TrustedSec</b></a> - latest news, and trends about cybersecurity.<br>
✅ <a href="https://portswigger.net/blog"><b>PortSwigger Web Security Blog</b></a> - about web app security vulns and top tips from our team of web security.<br>
✅ <a href="https://www.alienvault.com/blogs"><b>AT&T Cybersecurity blog</b></a> - news on emerging threats and practical advice to simplify threat detection.<br>
✅ <a href="https://thycotic.com/company/blog/"><b>Thycotic</b></a> - where CISOs and IT Admins come to learn about industry trends, IT security, and more.<br>
</p>

#####   Geeky Cybersecurity Podcasts


✅ <a href="https://risky.biz/netcasts/risky-business/"><b>Risky Business</b></a> - is a weekly information security podcast featuring news and in-depth interviews.<br>
✅ <a href="https://www.vice.com/en_us/topic/cyber"><b>Cyber, by Motherboard</b></a> - stories, and focus on the ideas  about cybersecurity.<br>
✅ <a href="https://www.tenable.com/podcast"><b>Tenable Podcast</b></a> - conversations and interviews related to Cyber Exposure, and more.<br>
✅ <a href="https://podcasts.apple.com/gb/podcast/cybercrime-investigations/id1428801405"><b>
Cybercrime Investigations</b></a> - podcast by Geoff White about cybercrimes.<br>
✅ <a href="https://themanyhats.club/tag/episodes/"><b>The many hats club</b></a> - featuring stories from a wide range of Infosec people (Whitehat, Greyhat and Blackhat).<br>
✅ <a href="https://darknetdiaries.com/"><b>Darknet Diaries</b></a> - true stories from the dark side of the Internet.<br>
✅ <a href="https://www.youtube.com/playlist?list=PL423I_gHbWUXah3dmt_q_XNp0NlGAKjis"><b>OSINTCurious Webcasts</b></a> - is the investigative curiosity that helps people be successful in OSINT.<br>
✅ <a href="https://www.youtube.com/user/SecurityWeeklyTV"><b>Security Weekly</b></a> - the latest information security and hacking news.<br>
</p>

#####   Geeky Cybersecurity Video Blogs


✅ <a href="https://www.youtube.com/channel/UCzvJStjySZVvOBsPl-Vgj0g"><b>rev3rse security</b></a> - offensive, binary exploitation, web app security, hardening, red team, blue team.<br>
✅ <a href="https://www.youtube.com/channel/UClcE-kVhqyiHCcjYwcpfj9w"><b>LiveOverflow</b></a> - a lot more advanced topics than what is typically offered in paid online courses - but for free.<br>
✅ <a href="https://www.youtube.com/infoseccynic"><b>J4vv4D</b></a> - the important information regarding our internet security.<br>
✅ <a href="https://cybertalks.co.uk/"><b>
CyberTalks</b></a> - talks, interviews, and article about cybersecurity.<br>
</p>

#####   Best Personal Twitter Accounts


✅ <a href="https://twitter.com/blackroomsec"><b>@blackroomsec</b></a> - a white-hat hacker/pentester. Intergalactic Minesweeper Champion 1990.<br>
✅ <a href="https://twitter.com/MarcoCiappelli"><b>@MarcoCiappelli</b></a> - Co-Founder @ITSPmagazine, at the intersection of IT security and society.<br>
✅ <a href="https://twitter.com/binitamshah"><b>@binitamshah</b></a> - Linux Evangelist. Malwares. Kernel Dev. Security Enthusiast.<br>
✅ <a href="https://twitter.com/joe_carson"><b>@joe_carson</b></a> - an InfoSec Professional and Tech Geek.<br>
✅ <a href="https://twitter.com/mikko"><b>@mikko</b></a> - CRO at F-Secure, Reverse Engineer, TED Speaker, Supervillain.<br>
✅ <a href="https://twitter.com/esrtweet"><b>@esrtweet</b></a> - often referred to as ESR, is an American software developer, and open-source software advocate.<br>
✅ <a href="https://twitter.com/gynvael"><b>@gynvael</b></a> - security researcher/programmer, @DragonSectorCTF founder/player, technical streamer.<br>
✅ <a href="https://twitter.com/x0rz"><b>@x0rz</b></a> - Security Researcher & Cyber Observer.<br>
✅ <a href="https://twitter.com/hasherezade"><b>@hasherezade</b></a> - programmer, malware analyst. Author of PEbear, PEsieve, libPeConv.<br>
✅ <a href="https://twitter.com/TinkerSec"><b>@TinkerSec</b></a> - tinkerer, cypherpunk, hacker.<br>
✅ <a href="https://twitter.com/alisaesage"><b>@alisaesage</b></a> - independent hacker and researcher.<br>
✅ <a href="https://twitter.com/SwiftOnSecurity"><b>@SwiftOnSecurity</b></a> - systems security, industrial safety, sysadmin, author of decentsecurity.com.<br>
✅ <a href="https://twitter.com/dakami"><b>@dakami</b></a> - is one of just seven people with the authority to restore the DNS root keys.<br>
✅ <a href="https://twitter.com/samykamkar"><b>@samykamkar</b></a> - is a famous "grey hat" hacker, security researcher, creator of the MySpace "Samy" worm.<br>
✅ <a href="https://twitter.com/securityweekly"><b>@securityweekly</b></a> - founder & CTO of Security Weekly podcast network.<br>
✅ <a href="https://twitter.com/jack_daniel"><b>@jack_daniel</b></a> - @SecurityBSides co-founder.<br>
✅ <a href="https://twitter.com/thegrugq"><b>@thegrugq</b></a> - Security Researcher.<br>
✅ <a href="https://twitter.com/matthew_d_green"><b>@matthew_d_green</b></a> - a cryptographer and professor at Johns Hopkins University.<br>
</p>

#####   Best Commercial Twitter Accounts


✅ <a href="https://twitter.com/haveibeenpwned"><b>@haveibeenpwned</b></a> - check if you have an account that has been compromised in a data breach.<br>
✅ <a href="https://twitter.com/bugcrowd"><b>@bugcrowd</b></a> - trusted by more of the Fortune 500 than any other crowdsourced security platform.<br>
✅ <a href="https://twitter.com/Malwarebytes"><b>@Malwarebytes</b></a> - most trusted security company. Unmatched threat visibility.<br>
✅ <a href="https://twitter.com/sansforensics"><b>@sansforensics</b></a> - the world's leading Digital Forensics and Incident Response provider.<br>
✅ <a href="https://twitter.com/attcyber"><b>@attcyber</b></a> - AT&T Cybersecurity’s Edge-to-Edge technologies provide threat intelligence, and more.<br>
✅ <a href="https://twitter.com/TheManyHatsClub"><b>@TheManyHatsClub</b></a> - an information security focused podcast and group of individuals from all walks of life.<br>
✅ <a href="https://twitter.com/hedgehogsec"><b>@hedgehogsec</b></a> - Hedgehog Cyber. Gibraltar and Manchester's top boutique information security firm.<br>
✅ <a href="https://twitter.com/NCSC"><b>@NCSC</b></a> - the National Cyber Security Centre. Helping to make the UK the safest place to live and work online.<br>
✅ <a href="https://twitter.com/Synacktiv"><b>@Synacktiv</b></a> - IT security experts.<br>
</p>

#####   A piece of history


✅ <a href="http://ftp.arl.army.mil/~mike/howto/"><b>How to Do Things at ARL</b></a> - how to configure modems, scan images, record CD-ROMs, and other.<b>*</b><br>
</p>

#####   Other


✅ <a href="https://www.youtube.com/watch?v=3QnD2c4Xovk"><b>Diffie-Hellman Key Exchange (short version)</b></a> - how Diffie-Hellman Key Exchange worked.<br>
</p>

#### Hacking/Penetration Testing [<sup>[TOC]</sup>](#anger-table-of-contents)

#####   Pentesters arsenal tools


✅ <a href="http://www.syhunt.com/sandcat/"><b>Sandcat Browser</b></a> - a penetration-oriented browser with plenty of advanced functionality already built in.<br>
✅ <a href="https://www.metasploit.com/"><b>Metasploit</b></a> - tool and framework for pentesting system, web and many more, contains a lot a ready to use exploit.<br>
✅ <a href="https://portswigger.net/burp"><b>Burp Suite</b></a> - tool for testing web app security, intercepting proxy to replay, inject, scan and fuzz.<br>
✅ <a href="https://www.owasp.org/index.php/OWASP_Zed_Attack_Proxy_Project"><b>OWASP Zed Attack Proxy</b></a> - intercepting proxy to replay, inject, scan and fuzz HTTP requests.<br>
✅ <a href="http://w3af.org/"><b>w3af</b></a> - is a Web Application Attack and Audit Framework.<br>
✅ <a href="https://mitmproxy.org/"><b>mitmproxy</b></a> - an interactive TLS-capable intercepting HTTP proxy for penetration testers.<br>
✅ <a href="https://cirt.net/Nikto2"><b>Nikto2</b></a> - web server scanner which performs comprehensive tests against web servers for multiple items.<br>
✅ <a href="http://sqlmap.org/"><b>sqlmap</b></a> - tool that automates the process of detecting and exploiting SQL injection flaws.<br>
✅ <a href="https://github.com/lanmaster53/recon-ng"><b>Recon-ng</b></a> - is a full-featured Web Reconnaissance framework written in Python.<br>
✅ <a href="https://github.com/Tib3rius/AutoRecon"><b>AutoRecon</b></a> - is a network reconnaissance tool which performs automated enumeration of services.<br>
✅ <a href="https://www.faradaysec.com/"><b>Faraday</b></a> - an Integrated Multiuser Pentest Environment.<br>
✅ <a href="https://github.com/s0md3v/Photon"><b>Photon</b></a> - incredibly fast crawler designed for OSINT.<br>
✅ <a href="https://github.com/s0md3v/XSStrike"><b>XSStrike</b></a> - most advanced XSS detection suite.<br>
✅ <a href="https://github.com/1N3/Sn1per"><b>Sn1per</b></a> - automated pentest framework for offensive security experts.<br>
✅ <a href="https://github.com/future-architect/vuls"><b>vuls</b></a> - is an agent-less vulnerability scanner for Linux, FreeBSD, and other.<br>
✅ <a href="https://github.com/google/tsunami-security-scanner"><b>tsunami</b></a> - is a general purpose network security scanner with an extensible plugin system.<br>
✅ <a href="https://github.com/michenriksen/aquatone"><b>aquatone</b></a> - a tool for domain flyovers.<br>
✅ <a href="https://github.com/GitHackTools/BillCipher"><b>BillCipher</b></a> - information gathering tool for a website or IP address.<br>
✅ <a href="https://github.com/Ekultek/WhatWaf"><b>WhatWaf</b></a> - detect and bypass web application firewalls and protection systems.<br>
✅ <a href="https://github.com/s0md3v/Corsy"><b>Corsy</b></a> - CORS misconfiguration scanner.<br>
✅ <a href="https://github.com/evyatarmeged/Raccoon"><b>Raccoon</b></a> - is a high performance offensive security tool for reconnaissance and vulnerability scanning.<br>
✅ <a href="https://github.com/Nekmo/dirhunt"><b>dirhunt</b></a> - find web directories without bruteforce.<br>
✅ <a href="https://www.openwall.com/john/"><b>John The Ripper</b></a> - is a fast password cracker, currently available for many flavors of Unix, Windows, and other.<br>
✅ <a href="https://hashcat.net/hashcat/"><b>hashcat</b></a> - world's fastest and most advanced password recovery utility.<br>
✅ <a href="http://lcamtuf.coredump.cx/p0f3/"><b>p0f</b></a> - is a tool to identify the players behind any incidental TCP/IP communications.<br>
✅ <a href="https://github.com/mozilla/ssh_scan"><b>ssh_scan</b></a> - a prototype SSH configuration and policy scanner.<br>
✅ <a href="https://github.com/woj-ciech/LeakLooker"><b>LeakLooker</b></a> - find open databases - powered by Binaryedge.io<br>
✅ <a href="https://github.com/offensive-security/exploitdb"><b>exploitdb</b></a> - searchable archive from The Exploit Database.<br>
✅ <a href="https://github.com/vulnersCom/getsploit"><b>getsploit</b></a> - is a command line utility for searching and downloading exploits.<br>
✅ <a href="https://github.com/zardus/ctf-tools"><b>ctf-tools</b></a> - some setup scripts for security research tools.<br>
✅ <a href="https://github.com/Gallopsled/pwntools"><b>pwntools</b></a> - CTF framework and exploit development library.<br>
✅ <a href="https://github.com/bl4de/security-tools"><b>security-tools</b></a> - collection of small security tools created mostly in Python. CTFs, pentests and so on.<br>
✅ <a href="https://github.com/leonteale/pentestpackage"><b>pentestpackage</b></a> - is a package of Pentest scripts.<br>
✅ <a href="https://github.com/dloss/python-pentest-tools"><b>python-pentest-tools</b></a> - python tools for penetration testers.<br>
✅ <a href="https://github.com/fuzzdb-project/fuzzdb"><b>fuzzdb</b></a> - dictionary of attack patterns and primitives for black-box application fault injection.<br>
✅ <a href="https://github.com/google/AFL"><b>AFL</b></a> - is a free software fuzzer maintained by Google.<br>
✅ <a href="https://github.com/AFLplusplus/AFLplusplus"><b>AFL++</b></a> - is AFL with community patches.<br>
✅ <a href="https://github.com/google/syzkaller"><b>syzkaller</b></a> - is an unsupervised, coverage-guided kernel fuzzer.<br>
✅ <a href="https://github.com/pwndbg/pwndbg"><b>pwndbg</b></a> - exploit development and reverse engineering with GDB made easy.<br>
✅ <a href="https://github.com/longld/peda"><b>GDB PEDA</b></a> - Python Exploit Development Assistance for GDB.<br>
✅ <a href="https://www.hex-rays.com/products/ida/index.shtml"><b>IDA</b></a> - multi-processor disassembler and debugger useful for reverse engineering malware.<br>
✅ <a href="https://github.com/radare/radare2"><b>radare2</b></a> - framework for reverse-engineering and analyzing binaries.<br>
✅ <a href="https://github.com/threat9/routersploit"><b>routersploit</b></a> - exploitation framework for embedded devices.<br>
✅ <a href="https://github.com/NationalSecurityAgency/ghidra"><b>Ghidra</b></a> - is a software reverse engineering (SRE) framework.<br>
✅ <a href="https://cutter.re/"><b>Cutter</b></a> - is an SRE platform integrating Ghidra's decompiler.<br>
✅ <a href="https://github.com/salesforce/vulnreport"><b>Vulnreport</b></a> - open-source pentesting management and automation platform by Salesforce Product Security.<br>
✅ <a href="https://github.com/sc0tfree/mentalist"><b>Mentalist</b></a> - is a graphical tool for custom wordlist generation.<br>
✅ <a href="https://github.com/archerysec/archerysec"><b>archerysec</b></a> - vulnerability assessment and management helps to perform scans and manage vulnerabilities.<br>
✅ <a href="https://github.com/j3ssie/Osmedeus"><b>Osmedeus</b></a> - fully automated offensive security tool for reconnaissance and vulnerability scanning.<br>
✅ <a href="https://github.com/beefproject/beef"><b>beef</b></a> - the browser exploitation framework project.<br>
✅ <a href="https://github.com/NullArray/AutoSploit"><b>AutoSploit</b></a> - automated mass exploiter.<br>
✅ <a href="https://github.com/TH3xACE/SUDO_KILLER"><b>SUDO_KILLER</b></a> - is a tool to identify and exploit sudo rules' misconfigurations and vulnerabilities.<br>
✅ <a href="https://github.com/VirusTotal/yara"><b>yara</b></a> - the pattern matching swiss knife.<br>
✅ <a href="https://github.com/gentilkiwi/mimikatz"><b>mimikatz</b></a> - a little tool to play with Windows security.<br>
✅ <a href="https://github.com/sherlock-project/sherlock"><b>sherlock</b></a> - hunt down social media accounts by username across social networks.<br>
✅ <a href="https://owasp.org/www-project-threat-dragon/"><b>OWASP Threat Dragon</b></a> - is a tool used to create threat model diagrams and to record possible threats.<br>
</p>

#####   Pentests bookmarks collection


✅ <a href="http://www.pentest-standard.org/index.php/Main_Page"><b>PTES</b></a> - the penetration testing execution standard.<br>
✅ <a href="https://www.amanhardikar.com/mindmaps/Practice.html"><b>Pentests MindMap</b></a> - amazing mind map with vulnerable apps and systems.<br>
✅ <a href="https://www.amanhardikar.com/mindmaps/webapptest.html"><b>WebApps Security Tests MindMap</b></a> - incredible mind map for WebApps security tests.<br>
✅ <a href="https://brutelogic.com.br/blog/"><b>Brute XSS</b></a> - master the art of Cross Site Scripting.<br>
✅ <a href="https://portswigger.net/web-security/cross-site-scripting/cheat-sheet"><b>XSS cheat sheet</b></a> - contains many vectors that can help you bypass WAFs and filters.<br>
✅ <a href="https://jivoi.github.io/2015/07/03/offensive-security-bookmarks/"><b>Offensive Security Bookmarks</b></a> - security bookmarks collection, all things that author need to pass OSCP.<br>
✅ <a href="https://github.com/coreb1t/awesome-pentest-cheat-sheets"><b>Awesome Pentest Cheat Sheets</b></a> - collection of the cheat sheets useful for pentesting.<br>
✅ <a href="https://github.com/Hack-with-Github/Awesome-Hacking"><b>Awesome Hacking by HackWithGithub</b></a> - awesome lists for hackers, pentesters and security researchers.<br>
✅ <a href="https://github.com/carpedm20/awesome-hacking"><b>Awesome Hacking by carpedm20</b></a> - a curated list of awesome hacking tutorials, tools and resources.<br>
✅ <a href="https://github.com/vitalysim/Awesome-Hacking-Resources"><b>Awesome Hacking Resources</b></a> - collection of hacking/penetration testing resources to make you better.<br>
✅ <a href="https://github.com/enaqx/awesome-pentest"><b>Awesome Pentest</b></a> - collection of awesome penetration testing resources, tools and other shiny things.<br>
✅ <a href="https://github.com/m4ll0k/Awesome-Hacking-Tools"><b>Awesome-Hacking-Tools</b></a> - is a curated list of awesome Hacking Tools.<br>
✅ <a href="https://github.com/ksanchezcld/Hacking_Cheat_Sheet"><b>Hacking Cheat Sheet</b></a> - author hacking and pentesting notes.<br>
✅ <a href="https://github.com/toolswatch/blackhat-arsenal-tools"><b>blackhat-arsenal-tools</b></a> - official Black Hat arsenal security tools repository.<br>
✅ <a href="https://www.peerlyst.com/posts/the-complete-list-of-infosec-related-cheat-sheets-claus-cramon"><b>Penetration Testing and WebApp Cheat Sheets</b></a> - the complete list of Infosec related cheat sheets.<br>
✅ <a href="https://github.com/The-Art-of-Hacking/h4cker"><b>Cyber Security Resources</b></a> - includes thousands of cybersecurity-related references and resources.<br>
✅ <a href="https://github.com/jhaddix/pentest-bookmarks"><b>Pentest Bookmarks</b></a> - there are a LOT of pentesting blogs.<br>
✅ <a href="https://github.com/OlivierLaflamme/Cheatsheet-God"><b>Cheatsheet-God</b></a> - Penetration Testing Reference Bank - OSCP/PTP & PTX Cheatsheet.<br>
✅ <a href="https://github.com/Cyb3rWard0g/ThreatHunter-Playbook"><b>ThreatHunter-Playbook</b></a> - to aid the development of techniques and hypothesis for hunting campaigns.<br>
✅ <a href="https://github.com/hmaverickadams/Beginner-Network-Pentesting"><b>Beginner-Network-Pentesting</b></a> - notes for beginner network pentesting course.<br>
✅ <a href="https://github.com/rewardone/OSCPRepo"><b>OSCPRepo</b></a> - is a list of resources that author have been gathering in preparation for the OSCP.<br>
✅ <a href="https://github.com/swisskyrepo/PayloadsAllTheThings"><b>PayloadsAllTheThings</b></a> - a list of useful payloads and bypass for Web Application Security and Pentest/CTF.<br>
✅ <a href="https://github.com/foospidy/payloads"><b>payloads</b></a> - git all the Payloads! A collection of web attack payloads.<br>
✅ <a href="https://github.com/payloadbox/command-injection-payload-list"><b>command-injection-payload-list</b></a> - command injection payload list.<br>
✅ <a href="https://github.com/jakejarvis/awesome-shodan-queries"><b>Awesome Shodan Search Queries</b></a> - great search queries to plug into Shodan.<br>
✅ <a href="https://github.com/s0md3v/AwesomeXSS"><b>AwesomeXSS</b></a> - is a collection of Awesome XSS resources.<br>
✅ <a href="https://github.com/JohnTroony/php-webshells"><b>php-webshells</b></a> - common php webshells.<br>
✅ <a href="https://highon.coffee/blog/penetration-testing-tools-cheat-sheet/"><b>Pentesting Tools Cheat Sheet</b></a> - a quick reference high level overview for typical penetration testing.<br>
✅ <a href="https://cheatsheetseries.owasp.org/"><b>OWASP Cheat Sheet Series</b></a> - is a collection of high value information on specific application security topics.<br>
✅ <a href="https://jeremylong.github.io/DependencyCheck/index.html"><b>OWASP dependency-check</b></a> - is an open source solution the OWASP Top 10 2013 entry.<br>
✅ <a href="https://www.owasp.org/index.php/OWASP_Proactive_Controls"><b>OWASP ProActive Controls</b></a> - OWASP Top 10 Proactive Controls 2018.<br>
✅ <a href="https://github.com/blaCCkHatHacEEkr/PENTESTING-BIBLE"><b>PENTESTING-BIBLE</b></a> - hacking & penetration testing & red team & cyber security resources.<br>
✅ <a href="https://github.com/nixawk/pentest-wiki"><b>pentest-wiki</b></a> - is a free online security knowledge library for pentesters/researchers.<br>
✅ <a href="https://media.defcon.org/"><b>DEF CON Media Server</b></a> - great stuff from DEFCON.<br>
✅ <a href="https://github.com/rshipp/awesome-malware-analysis"><b>Awesome Malware Analysis</b></a> - a curated list of awesome malware analysis tools and resources.<br>
✅ <a href="https://www.netsparker.com/blog/web-security/sql-injection-cheat-sheet/"><b>SQL Injection Cheat Sheet</b></a> - detailed technical stuff about the many different variants of the SQL Injection.<br>
✅ <a href="http://kb.entersoft.co.in/"><b>Entersoft Knowledge Base</b></a> - great and detailed reference about vulnerabilities.<br>
✅ <a href="http://html5sec.org/"><b>HTML5 Security Cheatsheet</b></a> - a collection of HTML5 related XSS attack vectors.<br>
✅ <a href="http://evuln.com/tools/xss-encoder/"><b>XSS String Encoder</b></a> - for generating XSS code to check your input validation filters against XSS.<br>
✅ <a href="https://gtfobins.github.io/"><b>GTFOBins</b></a> - list of Unix binaries that can be exploited by an attacker to bypass local security restrictions.<br>
✅ <a href="https://guif.re/"><b>Guifre Ruiz Notes</b></a> - collection of security, system, network and pentest cheatsheets.<br>
✅ <a href="http://blog.safebuff.com/2016/07/03/SSRF-Tips/index.html"><b>SSRF Tips</b></a> - a collection of SSRF Tips.<br>
✅ <a href="http://shell-storm.org/repo/CTF/"><b>shell-storm repo CTF</b></a> - great archive of CTFs.<br>
✅ <a href="https://github.com/bl4de/ctf"><b>ctf</b></a> - CTF (Capture The Flag) writeups, code snippets, notes, scripts.<br>
✅ <a href="https://github.com/orangetw/My-CTF-Web-Challenges"><b>My-CTF-Web-Challenges</b></a> - collection of CTF Web challenges.<br>
✅ <a href="https://github.com/OWASP/owasp-mstg"><b>MSTG</b></a> - The Mobile Security Testing Guide (MSTG) is a comprehensive manual for mobile app security testing.<br>
✅ <a href="https://github.com/sdcampbell/Internal-Pentest-Playbook"><b>Internal-Pentest-Playbook</b></a> - notes on the most common things for an Internal Network Penetration Test.<br>
✅ <a href="https://github.com/streaak/keyhacks"><b>KeyHacks</b></a> - shows quick ways in which API keys leaked by a bug bounty program can be checked.<br>
✅ <a href="https://github.com/securitum/research"><b>securitum/research</b></a> - various Proof of Concepts of security research performed by Securitum.<br>
✅ <a href="https://github.com/juliocesarfort/public-pentesting-reports"><b>public-pentesting-reports</b></a> - is a list of public pentest reports released by several consulting security groups.<br>
✅ <a href="https://github.com/djadmin/awesome-bug-bounty"><b>awesome-bug-bounty</b></a> - is a comprehensive curated list of available Bug Bounty.<br>
✅ <a href="https://github.com/ngalongc/bug-bounty-reference"><b>bug-bounty-reference</b></a> - is a list of bug bounty write-ups.<br>
✅ <a href="https://github.com/devanshbatham/Awesome-Bugbounty-Writeups"><b>Awesome-Bugbounty-Writeups</b></a> - is a curated list of bugbounty writeups.<br>
✅ <a href="https://pentester.land/list-of-bug-bounty-writeups.html"><b>Bug bounty writeups</b></a> - list of bug bounty writeups (2012-2020).<br>
✅ <a href="https://hackso.me/"><b>hackso.me</b></a> - a great journey into security.<br>
</p>

#####   Backdoors/exploits


✅ <a href="https://github.com/bartblaze/PHP-backdoors"><b>PHP-backdoors</b></a> - a collection of PHP backdoors. For educational or testing purposes only.<br>
</p>

#####   Wordlists and Weak passwords


✅ <a href="https://weakpass.com/"><b>Weakpass</b></a> - for any kind of bruteforce find wordlists or unleash the power of them all at once!<br>
✅ <a href="https://hashes.org/"><b>Hashes.org</b></a> - is a free online hash resolving service incorporating many unparalleled techniques.<br>
✅ <a href="https://github.com/danielmiessler/SecLists"><b>SecLists</b></a> - collection of multiple types of lists used during security assessments, collected in one place.<br>
✅ <a href="https://github.com/berzerk0/Probable-Wordlists"><b>Probable-Wordlists</b></a> - sorted by probability originally created for password generation and testing.<br>
✅ <a href="https://wiki.skullsecurity.org/index.php?title=Passwords"><b>skullsecurity passwords</b></a> - password dictionaries and leaked passwords repository.<br>
✅ <a href="https://bezpieka.org/polski-slownik-premium-polish-wordlist"><b>Polish PREMIUM Dictionary</b></a> - official dictionary created by the team on the forum bezpieka.org.<b>*</b> <sup><a href="https://sourceforge.net/projects/kali-linux/files/Wordlist/">1</sup><br>
✅ <a href="https://github.com/insidetrust/statistically-likely-usernames"><b>statistically-likely-usernames</b></a> - wordlists for creating statistically likely username lists.<br>
</p>

#####   Bounty platforms


✅ <a href="https://www.yeswehack.com/"><b>YesWeHack</b></a> - bug bounty platform with infosec jobs.<br>
✅ <a href="https://www.openbugbounty.org/"><b>Openbugbounty</b></a> - allows any security researcher reporting a vulnerability on any website.<br>
✅ <a href="https://www.hackerone.com/"><b>hackerone</b></a> - global hacker community to surface the most relevant security issues.<br>
✅ <a href="https://www.bugcrowd.com/"><b>bugcrowd</b></a> - crowdsourced cybersecurity for the enterprise.<br>
✅ <a href="https://crowdshield.com/"><b>Crowdshield</b></a> - crowdsourced security & bug bounty management.<br>
✅ <a href="https://www.synack.com/"><b>Synack</b></a> - crowdsourced security & bug bounty programs, crowd security intelligence platform, and more.<br>
✅ <a href="https://hacktrophy.com/en/"><b>Hacktrophy</b></a> - bug bounty platform.<br>
</p>

#####   Web Training Apps (local installation)


✅ <a href="https://www.owasp.org/index.php/OWASP_Vulnerable_Web_Applications_Directory_Project"><b>OWASP-VWAD</b></a> - comprehensive and well maintained registry of all known vulnerable web applications.<br>
✅ <a href="http://www.dvwa.co.uk/"><b>DVWA</b></a> - PHP/MySQL web application that is damn vulnerable.<br>
✅ <a href="https://metasploit.help.rapid7.com/docs/metasploitable-2"><b>metasploitable2</b></a> - vulnerable web application amongst security researchers.<br>
✅ <a href="https://github.com/rapid7/metasploitable3"><b>metasploitable3</b></a> - is a VM that is built from the ground up with a large amount of security vulnerabilities.<br>
✅ <a href="https://github.com/stamparm/DSVW"><b>DSVW</b></a> - is a deliberately vulnerable web application written in under 100 lines of code.<br>
✅ <a href="https://sourceforge.net/projects/mutillidae/"><b>OWASP Mutillidae II</b></a> - free, open source, deliberately vulnerable web-application.<br>
✅ <a href="https://www.owasp.org/index.php/OWASP_Juice_Shop_Project"><b>OWASP Juice Shop Project</b></a> - the most bug-free vulnerable application in existence.<br>
✅ <a href="https://www.owasp.org/index.php/Projects/OWASP_Node_js_Goat_Project"><b>OWASP Node js Goat Project</b></a> - OWASP Top 10 security risks apply to web apps developed using Node.js.<br>
✅ <a href="https://github.com/iteratec/juicy-ctf"><b>juicy-ctf</b></a> - run Capture the Flags and Security Trainings with OWASP Juice Shop.<br>
✅ <a href="https://github.com/OWASP/SecurityShepherd"><b>SecurityShepherd</b></a> - web and mobile application security training platform.<br>
✅ <a href="https://github.com/opendns/Security_Ninjas_AppSec_Training"><b>Security Ninjas</b></a> - open source application security training program.<br>
✅ <a href="https://github.com/rapid7/hackazon"><b>hackazon</b></a> - a modern vulnerable web app.<br>
✅ <a href="https://github.com/appsecco/dvna"><b>dvna</b></a> - damn vulnerable NodeJS application.<br>
✅ <a href="https://github.com/DefectDojo/django-DefectDojo"><b>django-DefectDojo</b></a> - is an open-source application vulnerability correlation and security orchestration tool.<br>
✅ <a href="https://google-gruyere.appspot.com/"><b>Google Gruyere</b></a> - web application exploits and defenses.<br>
✅ <a href="https://github.com/amolnaik4/bodhi"><b>Bodhi</b></a> - is a playground focused on learning the exploitation of client-side web vulnerabilities.<br>
✅ <a href="https://websploit.h4cker.org/"><b>Websploit</b></a> - single vm lab with the purpose of combining several vulnerable appliations in one environment.<br>
✅ <a href="https://github.com/vulhub/vulhub"><b>vulhub</b></a> - pre-built Vulnerable Environments based on docker-compose.<br>
✅ <a href="https://rhinosecuritylabs.com/aws/introducing-cloudgoat-2/"><b>CloudGoat 2</b></a> - the new & improved "Vulnerable by Design"
AWS deployment tool.<br>
✅ <a href="https://github.com/globocom/secDevLabs"><b>secDevLabs</b></a> - is a laboratory for learning secure web development in a practical manner.<br>
✅ <a href="https://github.com/incredibleindishell/CORS-vulnerable-Lab"><b>CORS-vulnerable-Lab</b></a> - sample vulnerable code and its exploit code.<br>
✅ <a href="https://github.com/moloch--/RootTheBox"><b>RootTheBox</b></a> - a Game of Hackers (CTF Scoreboard & Game Manager).<br>
✅ <a href="https://application.security/"><b>KONTRA</b></a> - application security training (OWASP Top Web & Api).<br>
</p>

#####   Labs (ethical hacking platforms/trainings/CTFs)


✅ <a href="https://www.offensive-security.com/"><b>Offensive Security</b></a> - true performance-based penetration testing training for over a decade.<br>
✅ <a href="https://www.hackthebox.eu/"><b>Hack The Box</b></a> - online platform allowing you to test your penetration testing skills.<br>
✅ <a href="https://www.hacking-lab.com/index.html"><b>Hacking-Lab</b></a> - online ethical hacking, computer network and security challenge platform.<br>
✅ <a href="http://pwnable.kr/index.php"><b>pwnable.kr</b></a> - non-commercial wargame site which provides various pwn challenges.<br>
✅ <a href="https://pwnable.tw/"><b>Pwnable.tw</b></a> - is a wargame site for hackers to test and expand their binary exploiting skills.<br>
✅ <a href="https://picoctf.com/"><b>picoCTF</b></a> - is a free computer security game targeted at middle and high school students.<br>
✅ <a href="https://ctflearn.com/"><b>CTFlearn</b></a> - is an online platform built to help ethical hackers learn and practice their cybersecurity knowledge.<br>
✅ <a href="https://ctftime.org/"><b>ctftime</b></a> - CTF archive and a place, where you can get some another CTF-related info.<br>
✅ <a href="https://silesiasecuritylab.com/"><b>Silesia Security Lab</b></a> - high quality security testing services.<br>
✅ <a href="https://practicalpentestlabs.com/"><b>Practical Pentest Labs</b></a> - pentest lab, take your Hacking skills to the next level.<br>
✅ <a href="https://www.root-me.org/?lang=en"><b>Root Me</b></a> - the fast, easy, and affordable way to train your hacking skills.<br>
✅ <a href="https://rozwal.to/login"><b>rozwal.to</b></a> - a great platform to train your pentesting skills.<br>
✅ <a href="https://tryhackme.com/"><b>TryHackMe</b></a> - learning Cyber Security made easy.<br>
✅ <a href="https://hackxor.net/"><b>hackxor</b></a> - is a realistic web application hacking game, designed to help players of all abilities develop their skills.<br>
✅ <a href="http://hack-yourself-first.com/"><b>Hack Yourself First</b></a> - it's full of nasty app sec holes.<br>
✅ <a href="http://overthewire.org/wargames/"><b>OverTheWire</b></a> - can help you to learn and practice security concepts in the form of fun-filled games.<br>
✅ <a href="https://labs.wizard-security.net/"><b>Wizard Labs</b></a> - is an online Penetration Testing Lab.<br>
✅ <a href="https://pentesterlab.com/"><b>PentesterLab</b></a> - provides vulnerable systems that can be used to test and understand vulnerabilities.<br>
✅ <a href="https://ringzer0ctf.com/"><b>RingZer0</b></a> - tons of challenges designed to test and improve your hacking skills.<br>
✅ <a href="http://www.try2hack.nl/"><b>try2hack</b></a> - several security-oriented challenges for your entertainment.<br>
✅ <a href="https://www.ubeeri.com/preconfig-labs"><b>Ubeeri</b></a> - preconfigured lab environments.<br>
✅ <a href="https://lab.pentestit.ru/"><b>Pentestit</b></a> - emulate IT infrastructures of real companies for legal pen testing and improving pentest skills.<br>
✅ <a href="https://microcorruption.com/login"><b>Microcorruption</b></a> - reversal challenges done in the web interface.<br>
✅ <a href="https://crackmes.one/"><b>Crackmes</b></a> - download crackmes to help improve your reverse engineering skills.<br>
✅ <a href="https://domgo.at/cxss/intro"><b>DomGoat</b></a> - DOM XSS security learning and practicing platform.<br>
✅ <a href="https://chall.stypr.com"><b>Stereotyped Challenges</b></a> - upgrade your web hacking techniques today!<br>
✅ <a href="https://www.vulnhub.com/"><b>Vulnhub</b></a> - allows anyone to gain practical 'hands-on' experience in digital security.<br>
✅ <a href="https://w3challs.com/"><b>W3Challs</b></a> - is a penetration testing training platform, which offers various computer challenges.<br>
✅ <a href="https://ringzer0ctf.com/challenges"><b>RingZer0 CTF</b></a> - offers you tons of challenges designed to test and improve your hacking skills.<br>
✅ <a href="https://hack.me/"><b>Hack.me</b></a> - a platform where you can build, host and share vulnerable web apps for educational purposes.<br>
✅ <a href="https://www.hackthis.co.uk/levels/"><b>HackThis!</b></a> - discover how hacks, dumps and defacements are performed and secure your website.<br>
✅ <a href="https://www.enigmagroup.org/#"><b>Enigma Group WebApp Training</b></a> - these challenges cover the exploits listed in the OWASP Top 10 Project.<br>
✅ <a href="https://challenges.re/"><b>Reverse Engineering Challenges</b></a> - challenges, exercises, problems and tasks - by level, by type, and more.<br>
✅ <a href="https://0x00sec.org/"><b>0x00sec</b></a> - the home of the Hacker - Malware, Reverse Engineering, and Computer Science.<br>
✅ <a href="https://www.wechall.net/challs"><b>We Chall</b></a> - there are exist a lots of different challenge types.<br>
✅ <a href="https://www.hackergateway.com/"><b>Hacker Gateway</b></a> - is the go-to place for hackers who want to test their skills.<br>
✅ <a href="https://www.hacker101.com/"><b>Hacker101</b></a> - is a free class for web security.<br>
✅ <a href="https://contained.af/"><b>contained.af</b></a> - a stupid game for learning about containers, capabilities, and syscalls.<br>
✅ <a href="http://flaws.cloud/"><b>flAWS challenge!</b></a> - a series of levels you'll learn about common mistakes and gotchas when using AWS.<br>
✅ <a href="https://cybersecurity.wtf"><b>CyberSec WTF</b></a> - provides web hacking challenges derived from bounty write-ups.<br>
✅ <a href="https://ctfchallenge.co.uk/login"><b>CTF Challenge</b></a> - CTF Web App challenges.<br>
✅ <a href="https://capturetheflag.withgoogle.com"><b>gCTF</b></a> - most of the challenges used in the Google CTF 2017.<br>
✅ <a href="https://www.hackthissite.org/pages/index/index.php"><b>Hack This Site</b></a> - is a free, safe and legal training ground for hackers.<br>
✅ <a href="https://attackdefense.com"><b>Attack & Defense</b></a> - is a browser-based cloud labs.<br>
✅ <a href="https://cryptohack.org/"><b>Cryptohack</b></a> - a fun platform for learning modern cryptography.<br>
✅ <a href="https://cryptopals.com/"><b>Cryptopals</b></a> - the cryptopals crypto challenges.<br>
</p>

#####   CTF platforms


✅ <a href="https://github.com/facebook/fbctf"><b>fbctf</b></a> - platform to host Capture the Flag competitions.<br>
✅ <a href="https://github.com/google/ctfscoreboard"><b>ctfscoreboard</b></a> - scoreboard for Capture The Flag competitions.<br>
</p>

#####   Other resources


✅ <a href="https://github.com/bugcrowd/bugcrowd_university"><b>Bugcrowd University</b></a> - open source education content for the researcher community.<br>
✅ <a href="https://github.com/rewardone/OSCPRepo"><b>OSCPRepo</b></a> - a list of resources and scripts that I have been gathering in preparation for the OSCP.<br>
✅ <a href="https://medium.com/@cxosmo/owasp-top-10-real-world-examples-part-1-a540c4ea2df5"><b>OWASP Top 10: Real-World Examples</b></a> - test your web apps with real-world examples (two-part series).<br>
✅ <a href="http://phrack.org/index.html"><b>phrack.org</b></a> - an awesome collection of articles from several respected hackers and other thinkers.<br>
✅ <a href="https://github.com/Gr1mmie/Practical-Ethical-Hacking-Resources"><b>Practical-Ethical-Hacking-Resources</b></a> - compilation of resources from TCM's Udemy Course.<br>
</p>

#### Your daily knowledge and news [<sup>[TOC]</sup>](#anger-table-of-contents)

#####   RSS Readers


✅ <a href="https://feedly.com/"><b>Feedly</b></a> - organize, read and share what matters to you.<br>
✅ <a href="https://www.inoreader.com/"><b>Inoreader</b></a> - similar to feedly with a support for filtering what you fetch from rss.<br>
</p>

#####   IRC Channels


✅ <a href="https://wiki.hackerspaces.org/IRC_Channel"><b>#hackerspaces</b></a> - hackerspace IRC channels.<br>
</p>

#####   Security


✅ <a href="https://thehackernews.com/"><b>The Hacker News</b></a> - leading news source dedicated to promoting awareness for security experts and hackers.<br>
✅ <a href="https://latesthackingnews.com/"><b>Latest Hacking News</b></a> - provides the latest hacking news, exploits and vulnerabilities for ethical hackers.<br>
✅ <a href="https://securitynewsletter.co/"><b>Security Newsletter</b></a> - security news as a weekly digest (email notifications).<br>
✅ <a href="https://security.googleblog.com/"><b>Google Online Security Blog</b></a> - the latest news and insights from Google on security and safety on the Internet.<br>
✅ <a href="https://blog.qualys.com/"><b>Qualys Blog</b></a> - expert network security guidance and news.<br>
✅ <a href="https://www.darkreading.com/"><b>DARKReading</b></a> - connecting the Information Security Community.<br>
✅ <a href="https://www.darknet.org.uk/"><b>Darknet</b></a> - latest hacking tools, hacker news, cybersecurity best practices, ethical hacking & pen-testing.<br>
✅ <a href="https://twitter.com/disclosedh1"><b>publiclyDisclosed</b></a> - public disclosure watcher who keeps you up to date about the recently disclosed bugs.<br>
✅ <a href="https://www.reddit.com/r/hacking/"><b>Reddit - Hacking</b></a> - a subreddit dedicated to hacking and hackers.<br>
✅ <a href="https://packetstormsecurity.com/"><b>Packet Storm</b></a> - information security services, news, files, tools, exploits, advisories and whitepapers.<br>
✅ <a href="https://sekurak.pl/"><b>Sekurak</b></a> - about security, penetration tests, vulnerabilities and many others (PL/EN).<br>
✅ <a href="https://nfsec.pl/"><b>nf.sec</b></a> - basic aspects and mechanisms of Linux operating system security (PL).<br>
</p>

#####   Other/All-in-one


✅ <a href="https://changelog.com/"><b>Changelog</b></a> - is a community of hackers; news & podcasts for developers and hackers.<br>
</p>

#### Other Cheat Sheets [<sup>[TOC]</sup>](#anger-table-of-contents)

###### Build your own DNS Servers


✅ <a href="https://calomel.org/unbound_dns.html"><b>Unbound DNS Tutorial</b></a> - a validating, recursive, and caching DNS server.<br>
✅ <a href="https://www.ctrl.blog/entry/knot-dns-resolver-tutorial.html"><b>Knot Resolver on Fedora</b></a> - how to get faster and more secure DNS resolution with Knot Resolver on Fedora.<br>
✅ <a href="https://www.aaflalo.me/2018/10/tutorial-setup-dns-over-https-server/"><b>DNS-over-HTTPS</b></a> - tutorial to setup your own DNS-over-HTTPS (DoH) server.<br>
✅ <a href="https://hacks.mozilla.org/2018/05/a-cartoon-intro-to-dns-over-https/"><b>dns-over-https</b></a> - a cartoon intro to DNS over HTTPS.<br>
✅ <a href="https://www.aaflalo.me/2019/03/dns-over-tls/"><b>DNS-over-TLS</b></a> - following to your DoH server, setup your DNS-over-TLS (DoT) server.<br>
✅ <a href="https://zwischenzugs.com/2018/01/26/how-and-why-i-run-my-own-dns-servers/"><b>DNS Servers</b></a> - how (and why) i run my own DNS Servers.<br>
</p>

###### Build your own Certificate Authority


✅ <a href="https://jamielinux.com/docs/openssl-certificate-authority/"><b>OpenSSL Certificate Authority</b></a> - build your own certificate authority (CA) using the OpenSSL tools.<br>
✅ <a href="https://github.com/smallstep/certificates"><b>step-ca Certificate Authority</b></a> - build your own certificate authority (CA) using open source step-ca.<br>
</p>

###### Build your own System/Virtual Machine


✅ <a href="https://github.com/cfenollosa/os-tutorial"><b>os-tutorial</b></a> - how to create an OS from scratch.<br>
✅ <a href="https://justinmeiners.github.io/lc3-vm/"><b>Write your Own Virtual Machine</b></a> - how to write your own virtual machine (VM).<br>
✅ <a href="https://github.com/cirosantilli/x86-bare-metal-examples"><b>x86 Bare Metal Examples</b></a> - dozens of minimal operating systems to learn x86 system programming.<br>
✅ <a href="https://github.com/djhworld/simple-computer"><b>simple-computer</b></a> - the scott CPU from "But How Do It Know?" by J. Clark Scott.<br>
✅ <a href="https://littleosbook.github.io/"><b>littleosbook</b></a> - the little book about OS development.<br>
</p>

###### DNS Servers list (privacy)

| <b><u>IP</u></b>     | <b><u>URL</u></b>                                                                       |
| :------------------- | :-------------------------------------------------------------------------------------- |
| **`84.200.69.80`**   | [dns.watch](https://dns.watch/)                                                         |
| **`94.247.43.254`**  | [opennic.org](https://www.opennic.org/)                                                 |
| **`64.6.64.6`**      | [verisign.com](https://www.verisign.com/en_US/security-services/public-dns/index.xhtml) |
| **`89.233.43.71`**   | [censurfridns.dk](https://blog.uncensoreddns.org/)                                      |
| **`1.1.1.1`**        | [cloudflare.com](https://1.1.1.1/)                                                      |
| **`94.130.110.185`** | [dnsprivacy.at](https://dnsprivacy.at/)                                                 |

###### TOP Browser extensions

| <b><u>Extension name</u></b> | <b><u>Description</u></b>                                                     |
| :--------------------------- | :---------------------------------------------------------------------------- |
| **`IPvFoo`**                 | Display the server IP address and HTTPS information across all page elements. |
| **`FoxyProxy`**              | Simplifies configuring browsers to access proxy-servers.                      |
| **`HTTPS Everywhere`**       | Automatically use HTTPS security on many sites.                               |
| **`uMatrix`**                | Point & click to forbid/allow any class of requests made by your browser.     |
| **`uBlock Origin`**          | An efficient blocker: easy on memory and CPU footprint.                       |
| **`Session Buddy`**          | Manage browser tabs and bookmarks with ease.                                  |
| **`SuperSorter`**            | Sort bookmarks recursively, delete duplicates, merge folders, and more.       |
| **`Clear Cache`**            | Clear your cache and browsing data.                                           |
| **`d3coder`**                | Encoding/Decoding plugin for various types of encoding.                       |
| **`Web Developer`**          | Adds a toolbar button with various web developer tools.                       |
| **`ThreatPinch Lookup`**     | Add threat intelligence hover tool tips.                                      |

###### TOP Burp extensions

| <b><u>Extension name</u></b>         | <b><u>Description</u></b>                                                       |
| :----------------------------------- | :------------------------------------------------------------------------------ |
| **`Active Scan++`**                  | Extends Burp's active and passive scanning capabilities.                        |
| **`Autorize`**                       | Automatically detects authorization enforcement.                                |
| **`AuthMatrix`**                     | A simple matrix grid to define the desired levels of access privilege.          |
| **`Logger++`**                       | Logs requests and responses for all Burp tools in a sortable table.             |
| **`Bypass WAF`**                     | Adds headers useful for bypassing some WAF devices.                             |
| **`JSON Beautifier`**                | Beautifies JSON content in the HTTP message viewer.                             |
| **`JSON Web Tokens`**                | Enables Burp to decode and manipulate JSON web tokens.                          |
| **`CSP Auditor`**                    | Displays CSP headers for responses, and passively reports CSP weaknesses.       |
| **`CSP-Bypass`**                     | Passively scans for CSP headers that contain known bypasses.                    |
| **`Hackvertor`**                     | Converts data using a tag-based configuration to apply various encoding.        |
| **`HTML5 Auditor`**                  | Scans for usage of risky HTML5 features.                                        |
| **`Software Vulnerability Scanner`** | Vulnerability scanner based on vulners.com audit API.                           |
| **`Turbo Intruder`**                 | Is a powerful bruteforcing tool.                                                |
| **`Upload Scanner`**                 | Upload a number of different file types, laced with different forms of payload. |

###### Hack Mozilla Firefox address bar

In Firefox's address bar, you can limit results by typing special characters before or after your term:

- `^` - for matches in your browsing history
- `*` - for matches in your bookmarks.
- `%` - for matches in your currently open tabs.
- `#` - for matches in page titles.
- `@` - for matches in web addresses.

###### Chrome hidden commands

- `chrome://chrome-urls` - list of all commands
- `chrome://flags` - enable experiments and development features
- `chrome://interstitials` - errors and warnings
- `chrome://net-internals` - network internals (events, dns, cache)
- `chrome://network-errors` - network errors
- `chrome://net-export` - start logging future network activity to a file
- `chrome://safe-browsing` - safe browsing options
- `chrome://user-actions` - record all user actions
- `chrome://restart` - restart chrome
- `chrome://dino` - ERR_INTERNET_DISCONNECTED...
- `cache:<website-address>` - view the cached version of the web page

###### Bypass WAFs by Shortening IP Address (by [0xInfection](https://twitter.com/0xInfection))

IP addresses can be shortened by dropping the zeroes:

```
http://1.0.0.1 → http://1.1
http://127.0.0.1 → http://127.1
http://192.168.0.1 → http://192.168.1

http://0xC0A80001 or http://3232235521 → 192.168.0.1
http://192.168.257 → 192.168.1.1
http://192.168.516 → 192.168.2.4
```

> This bypasses WAF filters for SSRF, open-redirect, etc where any IP as input gets blacklisted.

For more information please see [How to Obscure Any URL](http://www.pc-help.org/obscure.htm) and [Magic IP Address Shortcuts](https://stuff-things.net/2014/09/25/magic-ip-address-shortcuts/).

###### Hashing, encryption and encoding (by [Michal Špaček](https://twitter.com/spazef0rze))

_Hashing_

plaintext :arrow_right: hash<br>
hash :no_entry: plaintext

_Symmetric encryption_

plaintext :arrow_right: :key: :arrow_right: ciphertext<br>
plaintext :arrow_left: :key: :arrow_left: ciphertext<br>
(:key: shared key)

_Asymmetric encryption_

plaintext :arrow_right: :key: :arrow_right: ciphertext<br>
plaintext :arrow_left: :part_alternation_mark: :arrow_left: ciphertext<br>
(:key: public key, :part_alternation_mark: private key)<br>

_Encoding_

text :arrow_right: encoded<br>
text :arrow_left: encoded

#### One-liners [<sup>[TOC]</sup>](#anger-table-of-contents)

##### Table of Contents

- [terminal](#tool-terminal)
- [busybox](#tool-busybox)
- [mount](#tool-mount)
- [fuser](#tool-fuser)
- [lsof](#tool-lsof)
- [ps](#tool-ps)
- [top](#tool-top)
- [vmstat](#tool-vmstat)
- [iostat](#tool-iostat)
- [strace](#tool-strace)
- [kill](#tool-kill)
- [find](#tool-find)
- [diff](#tool-diff)
- [vimdiff](#tool-vimdiff)
- [tail](#tool-tail)
- [cpulimit](#tool-cpulimit)
- [pwdx](#tool-pwdx)
- [tr](#tool-tr)
- [chmod](#tool-chmod)
- [who](#tool-who)
- [last](#tool-last)
- [screen](#tool-screen)
- [script](#tool-script)
- [du](#tool-du)
- [inotifywait](#tool-inotifywait)
- [openssl](#tool-openssl)
- [secure-delete](#tool-secure-delete)
- [dd](#tool-dd)
- [gpg](#tool-gpg)
- [system-other](#tool-system-other)
- [curl](#tool-curl)
- [httpie](#tool-httpie)
- [ssh](#tool-ssh)
- [linux-dev](#tool-linux-dev)
- [tcpdump](#tool-tcpdump)
- [tcpick](#tool-tcpick)
- [ngrep](#tool-ngrep)
- [hping3](#tool-hping3)
- [nmap](#tool-nmap)
- [netcat](#tool-netcat)
- [socat](#tool-socat)
- [p0f](#tool-p0f)
- [gnutls-cli](#tool-gnutls-cli)
- [netstat](#tool-netstat)
- [rsync](#tool-rsync)
- [host](#tool-host)
- [dig](#tool-dig)
- [certbot](#tool-certbot)
- [network-other](#tool-network-other)
- [git](#tool-git)
- [awk](#tool-awk)
- [sed](#tool-sed)
- [grep](#tool-grep)
- [perl](#tool-perl)

##### Tool: [terminal](https://en.wikipedia.org/wiki/Linux_console)

###### Reload shell without exit

```bash
exec $SHELL -l
```

###### Close shell keeping all subprocess running

```bash
disown -a && exit
```

###### Exit without saving shell history

```bash
kill -9 $$
unset HISTFILE && exit
```

###### Perform a branching conditional

```bash
true && echo success
false || echo failed
```

###### Pipe stdout and stderr to separate commands

```bash
some_command > >(/bin/cmd_for_stdout) 2> >(/bin/cmd_for_stderr)
```

###### Redirect stdout and stderr each to separate files and print both to the screen

```bash
(some_command 2>&1 1>&3 | tee errorlog ) 3>&1 1>&2 | tee stdoutlog
```

###### List of commands you use most often

```bash
history | \
awk '{CMD[$2]++;count++;}END { for (a in CMD)print CMD[a] " " CMD[a]/count*100 "% " a;}' | \
grep -v "./" | \
column -c3 -s " " -t | \
sort -nr | nl |  head -n 20
```

###### Sterilize bash history

```bash
function sterile() {

  history | awk '$2 != "history" { $1=""; print $0 }' | egrep -vi "\
curl\b+.*(-E|--cert)\b+.*\b*|\
curl\b+.*--pass\b+.*\b*|\
curl\b+.*(-U|--proxy-user).*:.*\b*|\
curl\b+.*(-u|--user).*:.*\b*
.*(-H|--header).*(token|auth.*)\b+.*|\
wget\b+.*--.*password\b+.*\b*|\
http.?://.+:.+@.*\
" > $HOME/histbuff; history -r $HOME/histbuff;

}

export PROMPT_COMMAND="sterile"
```

> Look also: [A naive utility to censor credentials in command history](https://github.com/lbonanomi/go/blob/master/revisionist.go).

###### Quickly backup a file

```bash
cp filename{,.orig}
```

###### Empty a file (truncate to 0 size)

```bash
>filename
```

###### Delete all files in a folder that don't match a certain file extension

```bash
rm !(*.foo|*.bar|*.baz)
```

###### Pass multi-line string to a file

```bash
# cat  >filename ... - overwrite the file
# cat >>filename ... - append to a file
cat > filename << __EOF__
data data data
__EOF__
```

###### Edit a file on a remote host using vim

```bash
vim scp://user@host//etc/fstab
```

###### Create a directory and change into it at the same time

```bash
mkd() { mkdir -p "$@" && cd "$@"; }
```

###### Convert uppercase files to lowercase files

```bash
rename 'y/A-Z/a-z/' *
```

###### Print a row of characters across the terminal

```bash
printf "%`tput cols`s" | tr ' ' '#'
```

###### Show shell history without line numbers

```bash
history | cut -c 8-
fc -l -n 1 | sed 's/^\s*//'
```

###### Run command(s) after exit session

```bash
cat > /etc/profile << __EOF__
_after_logout() {

  username=$(whoami)

  for _pid in $(ps afx | grep sshd | grep "$username" | awk '{print $1}') ; do

    kill -9 $_pid

  done

}
trap _after_logout EXIT
__EOF__
```

###### Generate a sequence of numbers

```bash
for ((i=1; i<=10; i+=2)) ; do echo $i ; done
# alternative: seq 1 2 10

for ((i=5; i<=10; ++i)) ; do printf '%02d\n' $i ; done
# alternative: seq -w 5 10

for i in {1..10} ; do echo $i ; done
```

###### Simple Bash filewatching

```bash
unset MAIL; export MAILCHECK=1; export MAILPATH='$FILE_TO_WATCH?$MESSAGE'
```

---

##### Tool: [busybox](https://www.busybox.net/)

###### Static HTTP web server

```bash
busybox httpd -p $PORT -h $HOME [-c httpd.conf]
```

---

##### Tool: [mount](<https://en.wikipedia.org/wiki/Mount_(Unix)>)

###### Mount a temporary ram partition

```bash
mount -t tmpfs tmpfs /mnt -o size=64M
```

- `-t` - filesystem type
- `-o` - mount options

###### Remount a filesystem as read/write

```bash
mount -o remount,rw /
```

---

##### Tool: [fuser](<https://en.wikipedia.org/wiki/Fuser_(Unix)>)

###### Show which processes use the files/directories

```bash
fuser /var/log/daemon.log
fuser -v /home/supervisor
```

###### Kills a process that is locking a file

```bash
fuser -ki filename
```

- `-i` - interactive option

###### Kills a process that is locking a file with specific signal

```bash
fuser -k -HUP filename
```

- `--list-signals` - list available signal names

###### Show what PID is listening on specific port

```bash
fuser -v 53/udp
```

###### Show all processes using the named filesystems or block device

```bash
fuser -mv /var/www
```

---

##### Tool: [lsof](https://en.wikipedia.org/wiki/Lsof)

###### Show process that use internet connection at the moment

```bash
lsof -P -i -n
```

###### Show process that use specific port number

```bash
lsof -i tcp:443
```

###### Lists all listening ports together with the PID of the associated process

```bash
lsof -Pan -i tcp -i udp
```

###### List all open ports and their owning executables

```bash
lsof -i -P | grep -i "listen"
```

###### Show all open ports

```bash
lsof -Pnl -i
```

###### Show open ports (LISTEN)

```bash
lsof -Pni4 | grep LISTEN | column -t
```

###### List all files opened by a particular command

```bash
lsof -c "process"
```

###### View user activity per directory

```bash
lsof -u username -a +D /etc
```

###### Show 10 largest open files

```bash
lsof / | \
awk '{ if($7 > 1048576) print $7/1048576 "MB" " " $9 " " $1 }' | \
sort -n -u | tail | column -t
```

###### Show current working directory of a process

```bash
lsof -p <PID> | grep cwd
```

---

##### Tool: [ps](<https://en.wikipedia.org/wiki/Ps_(Unix)>)

###### Show a 4-way scrollable process tree with full details

```bash
ps awwfux | less -S
```

###### Processes per user counter

```bash
ps hax -o user | sort | uniq -c | sort -r
```

###### Show all processes by name with main header

```bash
ps -lfC nginx
```

---

##### Tool: [find](<https://en.wikipedia.org/wiki/Find_(Unix)>)

###### Find files that have been modified on your system in the past 60 minutes

```bash
find / -mmin 60 -type f
```

###### Find all files larger than 20M

```bash
find / -type f -size +20M
```

###### Find duplicate files (based on MD5 hash)

```bash
find -type f -exec md5sum '{}' ';' | sort | uniq --all-repeated=separate -w 33
```

###### Change permission only for files

```bash
cd /var/www/site && find . -type f -exec chmod 766 {} \;
cd /var/www/site && find . -type f -exec chmod 664 {} +
```

###### Change permission only for directories

```bash
cd /var/www/site && find . -type d -exec chmod g+x {} \;
cd /var/www/site && find . -type d -exec chmod g+rwx {} +
```

###### Find files and directories for specific user/group

```bash
# User:
find . -user <username> -print
find /etc -type f -user <username> -name "*.conf"

# Group:
find /opt -group <group>
find /etc -type f -group <group> -iname "*.conf"
```

###### Find files and directories for all without specific user/group

```bash
# User:
find . \! -user <username> -print

# Group:
find . \! -group <group>
```

###### Looking for files/directories that only have certain permission

```bash
# User
find . -user <username> -perm -u+rw # -rw-r--r--
find /home -user $(whoami) -perm 777 # -rwxrwxrwx

# Group:
find /home -type d -group <group> -perm 755 # -rwxr-xr-x
```

###### Delete older files than 60 days

```bash
find . -type f -mtime +60 -delete
```

###### Recursively remove all empty sub-directories from a directory

```bash
find . -depth  -type d  -empty -exec rmdir {} \;
```

###### How to find all hard links to a file

```bash
find </path/to/dir> -xdev -samefile filename
```

###### Recursively find the latest modified files

```bash
find . -type f -exec stat --format '%Y :%y %n' "{}" \; | sort -nr | cut -d: -f2- | head
```

###### Recursively find/replace of a string with sed

```bash
find . -not -path '*/\.git*' -type f -print0 | xargs -0 sed -i 's/foo/bar/g'
```

###### Recursively find/replace of a string in directories and file names

```bash
find . -depth -name '*test*' -execdir bash -c 'mv -v "$1" "${1//foo/bar}"' _ {} \;
```

###### Recursively find suid executables

```bash
find / \( -perm -4000 -o -perm -2000 \) -type f -exec ls -la {} \;
```

---

##### Tool: [top](<https://en.wikipedia.org/wiki/Top_(software)>)

###### Use top to monitor only all processes with the specific string

```bash
top -p $(pgrep -d , <str>)
```

- `<str>` - process containing string (eg. nginx, worker)

---

##### Tool: [vmstat](https://en.wikipedia.org/wiki/Vmstat)

###### Show current system utilization (fields in kilobytes)

```bash
vmstat 2 20 -t -w
```

- `2` - number of times with a defined time interval (delay)
- `20` - each execution of the command (count)
- `-t` - show timestamp
- `-w` - wide output
- `-S M` - output of the fields in megabytes instead of kilobytes

###### Show current system utilization will get refreshed every 5 seconds

```bash
vmstat 5 -w
```

###### Display report a summary of disk operations

```bash
vmstat -D
```

###### Display report of event counters and memory stats

```bash
vmstat -s
```

###### Display report about kernel objects stored in slab layer cache

```bash
vmstat -m
```

##### Tool: [iostat](https://en.wikipedia.org/wiki/Iostat)

###### Show information about the CPU usage, and I/O statistics about all the partitions

```bash
iostat 2 10 -t -m
```

- `2` - number of times with a defined time interval (delay)
- `10` - each execution of the command (count)
- `-t` - show timestamp
- `-m` - fields in megabytes (`-k` - in kilobytes, default)

###### Show information only about the CPU utilization

```bash
iostat 2 10 -t -m -c
```

###### Show information only about the disk utilization

```bash
iostat 2 10 -t -m -d
```

###### Show information only about the LVM utilization

```bash
iostat -N
```

---

##### Tool: [strace](https://en.wikipedia.org/wiki/Strace)

###### Track with child processes

```bash
# 1)
strace -f -p $(pidof glusterfsd)

# 2)
strace -f $(pidof php-fpm | sed 's/\([0-9]*\)/\-p \1/g')
```

###### Track process with 30 seconds limit

```bash
timeout 30 strace $(< /var/run/zabbix/zabbix_agentd.pid)
```

###### Track processes and redirect output to a file

```bash
ps auxw | grep '[a]pache' | awk '{print " -p " $2}' | \
xargs strace -o /tmp/strace-apache-proc.out
```

###### Track with print time spent in each syscall and limit length of print strings

```bash
ps auxw | grep '[i]init_policy' | awk '{print " -p " $2}' | \
xargs strace -f -e trace=network -T -s 10000
```

###### Track the open request of a network port

```bash
strace -f -e trace=bind nc -l 80
```

###### Track the open request of a network port (show TCP/UDP)

```bash
strace -f -e trace=network nc -lu 80
```

---

##### Tool: [kill](<https://en.wikipedia.org/wiki/Kill_(command)>)

###### Kill a process running on port

```bash
kill -9 $(lsof -i :<port> | awk '{l=$2} END {print l}')
```

---

##### Tool: [diff](https://en.wikipedia.org/wiki/Diff)

###### Compare two directory trees

```bash
diff <(cd directory1 && find | sort) <(cd directory2 && find | sort)
```

###### Compare output of two commands

```bash
diff <(cat /etc/passwd) <(cut -f2 /etc/passwd)
```

---

##### Tool: [vimdiff](http://vimdoc.sourceforge.net/htmldoc/diff.html)

###### Highlight the exact differences, based on characters and words

```bash
vimdiff file1 file2
```

###### Compare two JSON files

```bash
vimdiff <(jq -S . A.json) <(jq -S . B.json)
```

###### Compare Hex dump

```bash
d(){ vimdiff <(f $1) <(f $2);};f(){ hexdump -C $1|cut -d' ' -f3-|tr -s ' ';}; d ~/bin1 ~/bin2
```

###### diffchar

Save [diffchar](https://raw.githubusercontent.com/vim-scripts/diffchar.vim/master/plugin/diffchar.vim) @ `~/.vim/plugins`

Click `F7` to switch between diff modes

Usefull `vimdiff` commands:

- `qa` to exit all windows
- `:vertical resize 70` to resize window
- set window width `Ctrl+W [N columns]+(Shift+)<\>`

---

##### Tool: [tail](<https://en.wikipedia.org/wiki/Tail_(Unix)>)

###### Annotate tail -f with timestamps

```bash
tail -f file | while read ; do echo "$(date +%T.%N) $REPLY" ; done
```

###### Analyse an Apache access log for the most common IP addresses

```bash
tail -10000 access_log | awk '{print $1}' | sort | uniq -c | sort -n | tail
```

###### Analyse web server log and show only 5xx http codes

```bash
tail -n 100 -f /path/to/logfile | grep "HTTP/[1-2].[0-1]\" [5]"
```

---

##### Tool: [tar](<https://en.wikipedia.org/wiki/Tar_(computing)>)

###### System backup with exclude specific directories

```bash
cd /
tar -czvpf /mnt/system$(date +%d%m%Y%s).tgz --directory=/ \
--exclude=proc/* --exclude=sys/* --exclude=dev/* --exclude=mnt/* .
```

###### System backup with exclude specific directories (pigz)

```bash
cd /
tar cvpf /backup/snapshot-$(date +%d%m%Y%s).tgz --directory=/ \
--exclude=proc/* --exclude=sys/* --exclude=dev/* \
--exclude=mnt/* --exclude=tmp/* --use-compress-program=pigz .
```

---

##### Tool: [dump](<https://en.wikipedia.org/wiki/Dump_(program)>)

###### System backup to file

```bash
dump -y -u -f /backup/system$(date +%d%m%Y%s).lzo /
```

###### Restore system from lzo file

```bash
cd /
restore -rf /backup/system$(date +%d%m%Y%s).lzo
```

---

##### Tool: [cpulimit](http://cpulimit.sourceforge.net/)

###### Limit the cpu usage of a process

```bash
cpulimit -p pid -l 50
```

---

##### Tool: [pwdx](https://www.cyberciti.biz/faq/unix-linux-pwdx-command-examples-usage-syntax/)

###### Show current working directory of a process

```bash
pwdx <pid>
```

---

##### Tool: [taskset](https://www.cyberciti.biz/faq/taskset-cpu-affinity-command/)

###### Start a command on only one CPU core

```bash
taskset -c 0 <command>
```

---

##### Tool: [tr](<https://en.wikipedia.org/wiki/Tr_(Unix)>)

###### Show directories in the PATH, one per line

```bash
tr : '\n' <<<$PATH
```

---

##### Tool: [chmod](https://en.wikipedia.org/wiki/Chmod)

###### Remove executable bit from all files in the current directory

```bash
chmod -R -x+X *
```

###### Restore permission for /bin/chmod

```bash
# 1:
cp /bin/ls chmod.01
cp /bin/chmod chmod.01
./chmod.01 700 file

# 2:
/bin/busybox chmod 0700 /bin/chmod

# 3:
setfacl --set u::rwx,g::---,o::--- /bin/chmod
```

---

##### Tool: [who](<https://en.wikipedia.org/wiki/Who_(Unix)>)

###### Find last reboot time

```bash
who -b
```

###### Detect a user sudo-su'd into the current shell

```bash
[[ $(who -m | awk '{ print $1 }') == $(whoami) ]] || echo "You are su-ed to $(whoami)"
```

---

##### Tool: [last](https://www.howtoforge.com/linux-last-command/)

###### Was the last reboot a panic?

```bash
(last -x -f $(ls -1t /var/log/wtmp* | head -2 | tail -1); last -x -f /var/log/wtmp) | \
grep -A1 reboot | head -2 | grep -q shutdown && echo "Expected reboot" || echo "Panic reboot"
```

---

##### Tool: [screen](https://en.wikipedia.org/wiki/GNU_Screen)

###### Start screen in detached mode

```bash
screen -d -m <command>
```

###### Attach to an existing screen session

```bash
screen -r -d <pid>
```

---

##### Tool: [script](<https://en.wikipedia.org/wiki/Script_(Unix)>)

###### Record and replay terminal session

```bash
### Record session
# 1)
script -t 2>~/session.time -a ~/session.log

# 2)
script --timing=session.time session.log

### Replay session
scriptreplay --timing=session.time session.log
```

---

##### Tool: [du](https://en.wikipedia.org/wiki/GNU_Screen)

###### Show 20 biggest directories with 'K M G'

```bash
du | \
sort -r -n | \
awk '{split("K M G",v); s=1; while($1>1024){$1/=1024; s++} print int($1)" "v[s]"\t"$2}' | \
head -n 20
```

---

##### Tool: [inotifywait](https://en.wikipedia.org/wiki/GNU_Screen)

###### Init tool everytime a file in a directory is modified

```bash
while true ; do inotifywait -r -e MODIFY dir/ && ls dir/ ; done;
```

---

##### Tool: [openssl](https://www.openssl.org/)

###### Testing connection to the remote host

```bash
echo | openssl s_client -connect google.com:443 -showcerts
```

###### Testing connection to the remote host (debug mode)

```bash
echo | openssl s_client -connect google.com:443 -showcerts -tlsextdebug -status
```

###### Testing connection to the remote host (with SNI support)

```bash
echo | openssl s_client -showcerts -servername google.com -connect google.com:443
```

###### Testing connection to the remote host with specific ssl version

```bash
openssl s_client -tls1_2 -connect google.com:443
```

###### Testing connection to the remote host with specific ssl cipher

```bash
openssl s_client -cipher 'AES128-SHA' -connect google.com:443
```

###### Verify 0-RTT

```bash
_host="example.com"

cat > req.in << __EOF__
HEAD / HTTP/1.1
Host: $_host
Connection: close
__EOF__

openssl s_client -connect ${_host}:443 -tls1_3 -sess_out session.pem -ign_eof < req.in
openssl s_client -connect ${_host}:443 -tls1_3 -sess_in session.pem -early_data req.in
```

###### Generate private key without passphrase

```bash
# _len: 2048, 4096
( _fd="private.key" ; _len="2048" ; \
openssl genrsa -out ${_fd} ${_len} )
```

###### Generate private key with passphrase

```bash
# _ciph: des3, aes128, aes256
# _len: 2048, 4096
( _ciph="aes128" ; _fd="private.key" ; _len="2048" ; \
openssl genrsa -${_ciph} -out ${_fd} ${_len} )
```

###### Remove passphrase from private key

```bash
( _fd="private.key" ; _fd_unp="private_unp.key" ; \
openssl rsa -in ${_fd} -out ${_fd_unp} )
```

###### Encrypt existing private key with a passphrase

```bash
# _ciph: des3, aes128, aes256
( _ciph="aes128" ; _fd="private.key" ; _fd_pass="private_pass.key" ; \
openssl rsa -${_ciph} -in ${_fd} -out ${_fd_pass}
```

###### Check private key

```bash
( _fd="private.key" ; \
openssl rsa -check -in ${_fd} )
```

###### Get public key from private key

```bash
( _fd="private.key" ; _fd_pub="public.key" ; \
openssl rsa -pubout -in ${_fd} -out ${_fd_pub} )
```

###### Generate private key and CSR

```bash
( _fd="private.key" ; _fd_csr="request.csr" ; _len="2048" ; \
openssl req -out ${_fd_csr} -new -newkey rsa:${_len} -nodes -keyout ${_fd} )
```

###### Generate CSR

```bash
( _fd="private.key" ; _fd_csr="request.csr" ; \
openssl req -out ${_fd_csr} -new -key ${_fd} )
```

###### Generate CSR (metadata from existing certificate)

> Where `private.key` is the existing private key. As you can see you do not generate this CSR from your certificate (public key). Also you do not generate the "same" CSR, just a new one to request a new certificate.

```bash
( _fd="private.key" ; _fd_csr="request.csr" ; _fd_crt="cert.crt" ; \
openssl x509 -x509toreq -in ${_fd_crt} -out ${_fd_csr} -signkey ${_fd} )
```

###### Generate CSR with -config param

```bash
( _fd="private.key" ; _fd_csr="request.csr" ; \
openssl req -new -sha256 -key ${_fd} -out ${_fd_csr} \
-config <(
cat << __EOF__
[req]
default_bits        = 2048
default_md          = sha256
prompt              = no
distinguished_name  = dn
req_extensions      = req_ext

[ dn ]
C   = "<two-letter ISO abbreviation for your country>"
ST  = "<state or province where your organisation is legally located>"
L   = "<city where your organisation is legally located>"
O   = "<legal name of your organisation>"
OU  = "<section of the organisation>"
CN  = "<fully qualified domain name>"

[ req_ext ]
subjectAltName = @alt_names

[ alt_names ]
DNS.1 = <fully qualified domain name>
DNS.2 = <next domain>
DNS.3 = <next domain>
__EOF__
))
```

Other values in `[ dn ]`:

```
countryName            = "DE"                     # C=
stateOrProvinceName    = "Hessen"                 # ST=
localityName           = "Keller"                 # L=
postalCode             = "424242"                 # L/postalcode=
postalAddress          = "Keller"                 # L/postaladdress=
streetAddress          = "Crater 1621"            # L/street=
organizationName       = "apfelboymschule"        # O=
organizationalUnitName = "IT Department"          # OU=
commonName             = "example.com"            # CN=
emailAddress           = "webmaster@example.com"  # CN/emailAddress=
```

Example of `oids` (you'll probably also have to make OpenSSL know about the new fields required for EV by adding the following under `[new_oids]`):

```
[req]
...
oid_section         = new_oids

[ new_oids ]
postalCode = 2.5.4.17
streetAddress = 2.5.4.9
```

For more information please look at these great explanations:

- [RFC 5280](https://tools.ietf.org/html/rfc5280)
- [How to create multidomain certificates using config files](https://apfelboymchen.net/gnu/notes/openssl%20multidomain%20with%20config%20files.html)
- [Generate a multi domains certificate using config files](https://gist.github.com/romainnorberg/464758a6620228b977212a3cf20c3e08)
- [Your OpenSSL CSR command is out of date](https://expeditedsecurity.com/blog/openssl-csr-command/)
- [OpenSSL example configuration file](https://www.tbs-certificats.com/openssl-dem-server-cert.cnf)

###### List available EC curves

```bash
openssl ecparam -list_curves
```

###### Print ECDSA private and public keys

```bash
( _fd="private.key" ; \
openssl ec -in ${_fd} -noout -text )

# For x25519 only extracting public key
( _fd="private.key" ; _fd_pub="public.key" ; \
openssl pkey -in ${_fd} -pubout -out ${_fd_pub} )
```

###### Generate ECDSA private key

```bash
# _curve: prime256v1, secp521r1, secp384r1
( _fd="private.key" ; _curve="prime256v1" ; \
openssl ecparam -out ${_fd} -name ${_curve} -genkey )

# _curve: X25519
( _fd="private.key" ; _curve="x25519" ; \
openssl genpkey -algorithm ${_curve} -out ${_fd} )
```

###### Generate private key and CSR (ECC)

```bash
# _curve: prime256v1, secp521r1, secp384r1
( _fd="domain.com.key" ; _fd_csr="domain.com.csr" ; _curve="prime256v1" ; \
openssl ecparam -out ${_fd} -name ${_curve} -genkey ; \
openssl req -new -key ${_fd} -out ${_fd_csr} -sha256 )
```

###### Generate self-signed certificate

```bash
# _len: 2048, 4096
( _fd="domain.key" ; _fd_out="domain.crt" ; _len="2048" ; _days="365" ; \
openssl req -newkey rsa:${_len} -nodes \
-keyout ${_fd} -x509 -days ${_days} -out ${_fd_out} )
```

###### Generate self-signed certificate from existing private key

```bash
# _len: 2048, 4096
( _fd="domain.key" ; _fd_out="domain.crt" ; _days="365" ; \
openssl req -key ${_fd} -nodes \
-x509 -days ${_days} -out ${_fd_out} )
```

###### Generate self-signed certificate from existing private key and csr

```bash
# _len: 2048, 4096
( _fd="domain.key" ; _fd_csr="domain.csr" ; _fd_out="domain.crt" ; _days="365" ; \
openssl x509 -signkey ${_fd} -nodes \
-in ${_fd_csr} -req -days ${_days} -out ${_fd_out} )
```

###### Generate DH public parameters

```bash
( _dh_size="2048" ; \
openssl dhparam -out /etc/nginx/ssl/dhparam_${_dh_size}.pem "$_dh_size" )
```

###### Display DH public parameters

```bash
openssl pkeyparam -in dhparam.pem -text
```

###### Extract private key from pfx

```bash
( _fd_pfx="cert.pfx" ; _fd_key="key.pem" ; \
openssl pkcs12 -in ${_fd_pfx} -nocerts -nodes -out ${_fd_key} )
```

###### Extract private key and certs from pfx

```bash
( _fd_pfx="cert.pfx" ; _fd_pem="key_certs.pem" ; \
openssl pkcs12 -in ${_fd_pfx} -nodes -out ${_fd_pem} )
```

###### Extract certs from p7b

```bash
# PKCS#7 file doesn't include private keys.
( _fd_p7b="cert.p7b" ; _fd_pem="cert.pem" ; \
openssl pkcs7 -inform DER -outform PEM -in ${_fd_p7b} -print_certs > ${_fd_pem})
# or:
openssl pkcs7 -print_certs -in -in ${_fd_p7b} -out ${_fd_pem})
```

###### Convert DER to PEM

```bash
( _fd_der="cert.crt" ; _fd_pem="cert.pem" ; \
openssl x509 -in ${_fd_der} -inform der -outform pem -out ${_fd_pem} )
```

###### Convert PEM to DER

```bash
( _fd_der="cert.crt" ; _fd_pem="cert.pem" ; \
openssl x509 -in ${_fd_pem} -outform der -out ${_fd_der} )
```

###### Verification of the private key

```bash
( _fd="private.key" ; \
openssl rsa -noout -text -in ${_fd} )
```

###### Verification of the public key

```bash
# 1)
( _fd="public.key" ; \
openssl pkey -noout -text -pubin -in ${_fd} )

# 2)
( _fd="private.key" ; \
openssl rsa -inform PEM -noout -in ${_fd} &> /dev/null ; \
if [ $? = 0 ] ; then echo -en "OK\n" ; fi )
```

###### Verification of the certificate

```bash
( _fd="certificate.crt" ; # format: pem, cer, crt \
openssl x509 -noout -text -in ${_fd} )
```

###### Verification of the CSR

```bash
( _fd_csr="request.csr" ; \
openssl req -text -noout -in ${_fd_csr} )
```

###### Check the private key and the certificate are match

```bash
(openssl rsa -noout -modulus -in private.key | openssl md5 ; \
openssl x509 -noout -modulus -in certificate.crt | openssl md5) | uniq
```

###### Check the private key and the CSR are match

```bash
(openssl rsa -noout -modulus -in private.key | openssl md5 ; \
openssl req -noout -modulus -in request.csr | openssl md5) | uniq
```

---

##### Tool: [secure-delete](https://wiki.archlinux.org/index.php/Securely_wipe_disk)

###### Secure delete with shred

```bash
shred -vfuz -n 10 file
shred --verbose --random-source=/dev/urandom -n 1 /dev/sda
```

###### Secure delete with scrub

```bash
scrub -p dod /dev/sda
scrub -p dod -r file
```

###### Secure delete with badblocks

```bash
badblocks -s -w -t random -v /dev/sda
badblocks -c 10240 -s -w -t random -v /dev/sda
```

###### Secure delete with secure-delete

```bash
srm -vz /tmp/file
sfill -vz /local
sdmem -v
swapoff /dev/sda5 && sswap -vz /dev/sda5
```

---

##### Tool: [dd](<https://en.wikipedia.org/wiki/Dd_(Unix)>)

###### Show dd status every so often

```bash
dd <dd_params> status=progress
watch --interval 5 killall -USR1 dd
```

###### Redirect output to a file with dd

```bash
echo "string" | dd of=filename
```

---

##### Tool: [gpg](https://www.gnupg.org/)

###### Export public key

```bash
gpg --export --armor "<username>" > username.pkey
```

- `--export` - export all keys from all keyrings or specific key
- `-a|--armor` - create ASCII armored output

###### Encrypt file

```bash
gpg -e -r "<username>" dump.sql
```

- `-e|--encrypt` - encrypt data
- `-r|--recipient` - encrypt for specific <username>

###### Decrypt file

```bash
gpg -o dump.sql -d dump.sql.gpg
```

- `-o|--output` - use as output file
- `-d|--decrypt` - decrypt data (default)

###### Search recipient

```bash
gpg --keyserver hkp://keyserver.ubuntu.com --search-keys "<username>"
```

- `--keyserver` - set specific key server
- `--search-keys` - search for keys on a key server

###### List all of the packets in an encrypted file

```bash
gpg --batch --list-packets archive.gpg
gpg2 --batch --list-packets archive.gpg
```

---

##### Tool: [system-other](https://github.com/trimstray/the-book-of-secret-knowledge#tool-system-other)

###### Reboot system from init

```bash
exec /sbin/init 6
```

###### Init system from single user mode

```bash
exec /sbin/init
```

###### Show current working directory of a process

```bash
readlink -f /proc/<PID>/cwd
```

###### Show actual pathname of the executed command

```bash
readlink -f /proc/<PID>/exe
```

##### Tool: [curl](https://curl.haxx.se)

```bash
curl -Iks https://www.google.com
```

- `-I` - show response headers only
- `-k` - insecure connection when using ssl
- `-s` - silent mode (not display body)

```bash
curl -Iks --location -X GET -A "x-agent" https://www.google.com
```

- `--location` - follow redirects
- `-X` - set method
- `-A` - set user-agent

```bash
curl -Iks --location -X GET -A "x-agent" --proxy http://127.0.0.1:16379 https://www.google.com
```

- `--proxy [socks5://|http://]` - set proxy server

```bash
curl -o file.pdf -C - https://example.com/Aiju2goo0Ja2.pdf
```

- `-o` - write output to file
- `-C` - resume the transfer

###### Find your external IP address (external services)

```bash
curl ipinfo.io
curl ipinfo.io/ip
curl icanhazip.com
curl ifconfig.me/ip ; echo
```

###### Repeat URL request

```bash
# URL sequence substitution with a dummy query string:
curl -ks https://example.com/?[1-20]

# With shell 'for' loop:
for i in {1..20} ; do curl -ks https://example.com/ ; done
```

###### Check DNS and HTTP trace with headers for specific domains

```bash
### Set domains and external dns servers.
_domain_list=(google.com) ; _dns_list=("8.8.8.8" "1.1.1.1")

for _domain in "${_domain_list[@]}" ; do

  printf '=%.0s' {1..48}

  echo

  printf "[\\e[1;32m+\\e[m] resolve: %s\\n" "$_domain"

  for _dns in "${_dns_list[@]}" ; do

    # Resolve domain.
    host "${_domain}" "${_dns}"

    echo

  done

  for _proto in http https ; do

    printf "[\\e[1;32m+\\e[m] trace + headers: %s://%s\\n" "$_proto" "$_domain"

    # Get trace and http headers.
    curl -Iks -A "x-agent" --location "${_proto}://${_domain}"

    echo

  done

done

unset _domain_list _dns_list
```

---

##### Tool: [httpie](https://httpie.org/)

```bash
http -p Hh https://www.google.com
```

- `-p` - print request and response headers
  - `H` - request headers
  - `B` - request body
  - `h` - response headers
  - `b` - response body

```bash
http -p Hh https://www.google.com --follow --verify no
```

- `-F, --follow` - follow redirects
- `--verify no` - skip SSL verification

```bash
http -p Hh https://www.google.com --follow --verify no \
--proxy http:http://127.0.0.1:16379
```

- `--proxy [http:]` - set proxy server

##### Tool: [ssh](https://www.openssh.com/)

###### Escape Sequence

```
# Supported escape sequences:
~.  - terminate connection (and any multiplexed sessions)
~B  - send a BREAK to the remote system
~C  - open a command line
~R  - Request rekey (SSH protocol 2 only)
~^Z - suspend ssh
~#  - list forwarded connections
~&  - background ssh (when waiting for connections to terminate)
~?  - this message
~~  - send the escape character by typing it twice
```

###### Compare a remote file with a local file

```bash
ssh user@host cat /path/to/remotefile | diff /path/to/localfile -
```

###### SSH connection through host in the middle

```bash
ssh -t reachable_host ssh unreachable_host
```

###### Run command over SSH on remote host

```bash
cat > cmd.txt << __EOF__
cat /etc/hosts
__EOF__

ssh host -l user $(<cmd.txt)
```

###### Get public key from private key

```bash
ssh-keygen -y -f ~/.ssh/id_rsa
```

###### Get all fingerprints

```bash
ssh-keygen -l -f .ssh/known_hosts
```

###### SSH authentication with user password

```bash
ssh -o PreferredAuthentications=password -o PubkeyAuthentication=no user@remote_host
```

###### SSH authentication with publickey

```bash
ssh -o PreferredAuthentications=publickey -o PubkeyAuthentication=yes -i id_rsa user@remote_host
```

###### Simple recording SSH session

```bash
function _ssh_sesslog() {

  _sesdir="<path/to/session/logs>"

  mkdir -p "${_sesdir}" && \
  ssh $@ 2>&1 | tee -a "${_sesdir}/$(date +%Y%m%d).log"

}

# Alias:
alias ssh='_ssh_sesslog'
```

###### Using Keychain for SSH logins

```bash
### Delete all of ssh-agent's keys.
function _scl() {

  /usr/bin/keychain --clear

}

### Add key to keychain.
function _scg() {

  /usr/bin/keychain /path/to/private-key
  source "$HOME/.keychain/$HOSTNAME-sh"

}
```

###### SSH login without processing any login scripts

```bash
ssh -tt user@host bash
```

###### SSH local port forwarding

Example 1:

```bash
# Forwarding our local 2250 port to nmap.org:443 from localhost through localhost
host1> ssh -L 2250:nmap.org:443 localhost

# Connect to the service:
host1> curl -Iks --location -X GET https://localhost:2250
```

Example 2:

```bash
# Forwarding our local 9051 port to db.d.x:5432 from localhost through node.d.y
host1> ssh -nNT -L 9051:db.d.x:5432 node.d.y

# Connect to the service:
host1> psql -U db_user -d db_dev -p 9051 -h localhost
```

- `-n` - redirects stdin from `/dev/null`
- `-N` - do not execute a remote command
- `-T` - disable pseudo-terminal allocation

###### SSH remote port forwarding

```bash
# Forwarding our local 9051 port to db.d.x:5432 from host2 through node.d.y
host1> ssh -nNT -R 9051:db.d.x:5432 node.d.y

# Connect to the service:
host2> psql -U postgres -d postgres -p 8000 -h localhost
```

---

##### Tool: [linux-dev](https://www.tldp.org/LDP/abs/html/devref1.html)

###### Testing remote connection to port

```bash
timeout 1 bash -c "</dev/<proto>/<host>/<port>" >/dev/null 2>&1 ; echo $?
```

- `<proto` - set protocol (tcp/udp)
- `<host>` - set remote host
- `<port>` - set destination port

###### Read and write to TCP or UDP sockets with common bash tools

```bash
exec 5<>/dev/tcp/<host>/<port>; cat <&5 & cat >&5; exec 5>&-
```

---

##### Tool: [tcpdump](http://www.tcpdump.org/)

###### Filter incoming (on interface) traffic (specific <ip:port>)

```bash
tcpdump -ne -i eth0 -Q in host 192.168.252.1 and port 443
```

- `-n` - don't convert addresses (`-nn` will not resolve hostnames or ports)
- `-e` - print the link-level headers
- `-i [iface|any]` - set interface
- `-Q|-D [in|out|inout]` - choose send/receive direction (`-D` - for old tcpdump versions)
- `host [ip|hostname]` - set host, also `[host not]`
- `[and|or]` - set logic
- `port [1-65535]` - set port number, also `[port not]`

###### Filter incoming (on interface) traffic (specific <ip:port>) and write to a file

```bash
tcpdump -ne -i eth0 -Q in host 192.168.252.1 and port 443 -c 5 -w tcpdump.pcap
```

- `-c [num]` - capture only num number of packets
- `-w [filename]` - write packets to file, `-r [filename]` - reading from file

###### Capture all ICMP packets

```bash
tcpdump -nei eth0 icmp
```

###### Check protocol used (TCP or UDP) for service

```bash
tcpdump -nei eth0 tcp port 22 -vv -X | egrep "TCP|UDP"
```

###### Display ASCII text (to parse the output using grep or other)

```bash
tcpdump -i eth0 -A -s0 port 443
```

###### Grab everything between two keywords

```bash
tcpdump -i eth0 port 80 -X | sed -n -e '/username/,/=ldap/ p'
```

###### Grab user and pass ever plain http

```bash
tcpdump -i eth0  port http -l -A | egrep -i \
'pass=|pwd=|log=|login=|user=|username=|pw=|passw=|passwd=|password=|pass:|user:|username:|password:|login:|pass |user ' \
--color=auto --line-buffered -B20
```

###### Extract HTTP User Agent from HTTP request header

```bash
tcpdump -ei eth0 -nn -A -s1500 -l | grep "User-Agent:"
```

###### Capture only HTTP GET and POST packets

```bash
tcpdump -ei eth0 -s 0 -A -vv \
'tcp[((tcp[12:1] & 0xf0) >> 2):4] = 0x47455420' or 'tcp[((tcp[12:1] & 0xf0) >> 2):4] = 0x504f5354'
```

or simply:

```bash
tcpdump -ei eth0 -s 0 -v -n -l | egrep -i "POST /|GET /|Host:"
```

###### Rotate capture files

```bash
tcpdump -ei eth0 -w /tmp/capture-%H.pcap -G 3600 -C 200
```

- `-G <num>` - pcap will be created every `<num>` seconds
- `-C <size>` - close the current pcap and open a new one if is larger than `<size>`

###### Top hosts by packets

```bash
tcpdump -ei enp0s25 -nnn -t -c 200 | cut -f 1,2,3,4 -d '.' | sort | uniq -c | sort -nr | head -n 20
```

###### Excludes any RFC 1918 private address

```bash
tcpdump -nei eth0 'not (src net (10 or 172.16/12 or 192.168/16) and dst net (10 or 172.16/12 or 192.168/16))'
```

---

##### Tool: [tcpick](http://tcpick.sourceforge.net/)

###### Analyse packets in real-time

```bash
while true ; do tcpick -a -C -r dump.pcap ; sleep 2 ; clear ; done
```

---

##### Tool: [ngrep](http://ngrep.sourceforge.net/usage.html)

```bash
ngrep -d eth0 "www.domain.com" port 443
```

- `-d [iface|any]` - set interface
- `[domain]` - set hostname
- `port [1-65535]` - set port number

```bash
ngrep -d eth0 "www.domain.com" src host 10.240.20.2 and port 443
```

- `(host [ip|hostname])` - filter by ip or hostname
- `(port [1-65535])` - filter by port number

```bash
ngrep -d eth0 -qt -O ngrep.pcap "www.domain.com" port 443
```

- `-q` - quiet mode (only payloads)
- `-t` - added timestamps
- `-O [filename]` - save output to file, `-I [filename]` - reading from file

```bash
ngrep -d eth0 -qt 'HTTP' 'tcp'
```

- `HTTP` - show http headers
- `tcp|udp` - set protocol
- `[src|dst] host [ip|hostname]` - set direction for specific node

```bash
ngrep -l -q -d eth0 -i "User-Agent: curl*"
```

- `-l` - stdout line buffered
- `-i` - case-insensitive search

---

##### Tool: [hping3](http://www.hping.org/)

```bash
hping3 -V -p 80 -s 5050 <scan_type> www.google.com
```

- `-V|--verbose` - verbose mode
- `-p|--destport` - set destination port
- `-s|--baseport` - set source port
- `<scan_type>` - set scan type
  - `-F|--fin` - set FIN flag, port open if no reply
  - `-S|--syn` - set SYN flag
  - `-P|--push` - set PUSH flag
  - `-A|--ack` - set ACK flag (use when ping is blocked, RST response back if the port is open)
  - `-U|--urg` - set URG flag
  - `-Y|--ymas` - set Y unused flag (0x80 - nullscan), port open if no reply
  - `-M 0 -UPF` - set TCP sequence number and scan type (URG+PUSH+FIN), port open if no reply

```bash
hping3 -V -c 1 -1 -C 8 www.google.com
```

- `-c [num]` - packet count
- `-1` - set ICMP mode
- `-C|--icmptype [icmp-num]` - set icmp type (default icmp-echo = 8)

```bash
hping3 -V -c 1000000 -d 120 -S -w 64 -p 80 --flood --rand-source <remote_host>
```

- `--flood` - sent packets as fast as possible (don't show replies)
- `--rand-source` - random source address mode
- `-d --data` - data size
- `-w|--win` - winsize (default 64)

---

##### Tool: [nmap](https://nmap.org/)

###### Ping scans the network

```bash
nmap -sP 192.168.0.0/24
```

###### Show only open ports

```bash
nmap -F --open 192.168.0.0/24
```

###### Full TCP port scan using with service version detection

```bash
nmap -p 1-65535 -sV -sS -T4 192.168.0.0/24
```

###### Nmap scan and pass output to Nikto

```bash
nmap -p80,443 192.168.0.0/24 -oG - | nikto.pl -h -
```

###### Recon specific ip:service with Nmap NSE scripts stack

```bash
# Set variables:
_hosts="192.168.250.10"
_ports="80,443"

# Set Nmap NSE scripts stack:
_nmap_nse_scripts="+dns-brute,\
                   +http-auth-finder,\
                   +http-chrono,\
                   +http-cookie-flags,\
                   +http-cors,\
                   +http-cross-domain-policy,\
                   +http-csrf,\
                   +http-dombased-xss,\
                   +http-enum,\
                   +http-errors,\
                   +http-git,\
                   +http-grep,\
                   +http-internal-ip-disclosure,\
                   +http-jsonp-detection,\
                   +http-malware-host,\
                   +http-methods,\
                   +http-passwd,\
                   +http-phpself-xss,\
                   +http-php-version,\
                   +http-robots.txt,\
                   +http-sitemap-generator,\
                   +http-shellshock,\
                   +http-stored-xss,\
                   +http-title,\
                   +http-unsafe-output-escaping,\
                   +http-useragent-tester,\
                   +http-vhosts,\
                   +http-waf-detect,\
                   +http-waf-fingerprint,\
                   +http-xssed,\
                   +traceroute-geolocation.nse,\
                   +ssl-enum-ciphers,\
                   +whois-domain,\
                   +whois-ip"

# Set Nmap NSE script params:
_nmap_nse_scripts_args="dns-brute.domain=${_hosts},http-cross-domain-policy.domain-lookup=true,"
_nmap_nse_scripts_args+="http-waf-detect.aggro,http-waf-detect.detectBodyChanges,"
_nmap_nse_scripts_args+="http-waf-fingerprint.intensive=1"

# Perform scan:
nmap --script="$_nmap_nse_scripts" --script-args="$_nmap_nse_scripts_args" -p "$_ports" "$_hosts"
```

---

##### Tool: [netcat](http://netcat.sourceforge.net/)

```bash
nc -kl 5000
```

- `-l` - listen for an incoming connection
- `-k` - listening after client has disconnected
- `>filename.out` - save receive data to file (optional)

```bash
nc 192.168.0.1 5051 < filename.in
```

- `< filename.in` - send data to remote host

```bash
nc -vz 10.240.30.3 5000
```

- `-v` - verbose output
- `-z` - scan for listening daemons

```bash
nc -vzu 10.240.30.3 1-65535
```

- `-u` - scan only udp ports

###### Transfer data file (archive)

```bash
server> nc -l 5000 | tar xzvfp -
client> tar czvfp - /path/to/dir | nc 10.240.30.3 5000
```

###### Launch remote shell

```bash
# 1)
server> nc -l 5000 -e /bin/bash
client> nc 10.240.30.3 5000

# 2)
server> rm -f /tmp/f; mkfifo /tmp/f
server> cat /tmp/f | /bin/bash -i 2>&1 | nc -l 127.0.0.1 5000 > /tmp/f
client> nc 10.240.30.3 5000
```

###### Simple file server

```bash
while true ; do nc -l 5000 | tar -xvf - ; done
```

###### Simple minimal HTTP Server

```bash
while true ; do nc -l -p 1500 -c 'echo -e "HTTP/1.1 200 OK\n\n $(date)"' ; done
```

###### Simple HTTP Server

> Restarts web server after each request - remove `while` condition for only single connection.

```bash
cat > index.html << __EOF__
<!doctype html>
    <head>
        <meta charset="utf-8">
        <meta http-equiv="X-UA-Compatible" content="IE=edge,chrome=1">
        <title></title>
        <meta name="description" content="">
        <meta name="viewport" content="width=device-width, initial-scale=1">
    </head>
    <body>

    

      Hello! It's a site.

    </p>

    </body>
</html>
__EOF__
```

```bash
server> while : ; do \
(echo -ne "HTTP/1.1 200 OK\r\nContent-Length: $(wc -c <index.html)\r\n\r\n" ; cat index.html;) | \
nc -l -p 5000 \
; done
```

- `-p` - port number

###### Simple HTTP Proxy (single connection)

```bash
#!/usr/bin/env bash

if [[ $# != 2 ]] ; then
  printf "%s\\n" \
         "usage: ./nc-proxy listen-port bk_host:bk_port"
fi

_listen_port="$1"
_bk_host=$(echo "$2" | cut -d ":" -f1)
_bk_port=$(echo "$2" | cut -d ":" -f2)

printf "  lport: %s\\nbk_host: %s\\nbk_port: %s\\n\\n" \
       "$_listen_port" "$_bk_host" "$_bk_port"

_tmp=$(mktemp -d)
_back="$_tmp/pipe.back"
_sent="$_tmp/pipe.sent"
_recv="$_tmp/pipe.recv"

trap 'rm -rf "$_tmp"' EXIT

mkfifo -m 0600 "$_back" "$_sent" "$_recv"

sed "s/^/=> /" <"$_sent" &
sed "s/^/<=  /" <"$_recv" &

nc -l -p "$_listen_port" <"$_back" | \
tee "$_sent" | \
nc "$_bk_host" "$_bk_port" | \
tee "$_recv" >"$_back"
```

```bash
server> chmod +x nc-proxy && ./nc-proxy 8080 192.168.252.10:8000
  lport: 8080
bk_host: 192.168.252.10
bk_port: 8000

client> http -p h 10.240.30.3:8080
HTTP/1.1 200 OK
Accept-Ranges: bytes
Cache-Control: max-age=31536000
Content-Length: 2748
Content-Type: text/html; charset=utf-8
Date: Sun, 01 Jul 2018 20:12:08 GMT
Last-Modified: Sun, 01 Apr 2018 21:53:37 GMT
```

###### Create a single-use TCP or UDP proxy

```bash
### TCP -> TCP
nc -l -p 2000 -c "nc [ip|hostname] 3000"

### TCP -> UDP
nc -l -p 2000 -c "nc -u [ip|hostname] 3000"

### UDP -> UDP
nc -l -u -p 2000 -c "nc -u [ip|hostname] 3000"

### UDP -> TCP
nc -l -u -p 2000 -c "nc [ip|hostname] 3000"
```

---

##### Tool: [gnutls-cli](https://gnutls.org/manual/html_node/gnutls_002dcli-Invocation.html)

###### Testing connection to remote host (with SNI support)

```bash
gnutls-cli -p 443 google.com
```

###### Testing connection to remote host (without SNI support)

```bash
gnutls-cli --disable-sni -p 443 google.com
```

---

##### Tool: [socat](http://www.dest-unreach.org/socat/doc/socat.html)

###### Testing remote connection to port

```bash
socat - TCP4:10.240.30.3:22
```

- `-` - standard input (STDIO)
- `TCP4:<params>` - set tcp4 connection with specific params
  - `[hostname|ip]` - set hostname/ip
  - `[1-65535]` - set port number

###### Redirecting TCP-traffic to a UNIX domain socket under Linux

```bash
socat TCP-LISTEN:1234,bind=127.0.0.1,reuseaddr,fork,su=nobody,range=127.0.0.0/8 UNIX-CLIENT:/tmp/foo
```

- `TCP-LISTEN:<params>` - set tcp listen with specific params
  - `[1-65535]` - set port number
  - `bind=[hostname|ip]` - set bind hostname/ip
  - `reuseaddr` - allows other sockets to bind to an address
  - `fork` - keeps the parent process attempting to produce more connections
  - `su=nobody` - set user
  - `range=[ip-range]` - ip range
- `UNIX-CLIENT:<params>` - communicates with the specified peer socket
  - `filename` - define socket

---

##### Tool: [p0f](http://lcamtuf.coredump.cx/p0f3/)

###### Set iface in promiscuous mode and dump traffic to the log file

```bash
p0f -i enp0s25 -p -d -o /dump/enp0s25.log
```

- `-i` - listen on the specified interface
- `-p` - set interface in promiscuous mode
- `-d` - fork into background
- `-o` - output file

---

##### Tool: [netstat](https://en.wikipedia.org/wiki/Netstat)

###### Graph # of connections for each hosts

```bash
netstat -an | awk '/ESTABLISHED/ { split($5,ip,":"); if (ip[1] !~ /^$/) print ip[1] }' | \
sort | uniq -c | awk '{ printf("%s\t%s\t",$2,$1) ; for (i = 0; i < $1; i++) {printf("*")}; print "" }'
```

###### Monitor open connections for specific port including listen, count and sort it per IP

```bash
watch "netstat -plan | grep :443 | awk {'print \$5'} | cut -d: -f 1 | sort | uniq -c | sort -nk 1"
```

###### Grab banners from local IPv4 listening ports

```bash
netstat -nlt | grep 'tcp ' | grep -Eo "[1-9][0-9]*" | xargs -I {} sh -c "echo "" | nc -v -n -w1 127.0.0.1 {}"
```

---

##### Tool: [rsync](https://en.wikipedia.org/wiki/Rsync)

###### Rsync remote data as root using sudo

```bash
rsync --rsync-path 'sudo rsync' username@hostname:/path/to/dir/ /local/
```

---

##### Tool: [host](<https://en.wikipedia.org/wiki/Host_(Unix)>)

###### Resolves the domain name (using external dns server)

```bash
host google.com 9.9.9.9
```

###### Checks the domain administrator (SOA record)

```bash
host -t soa google.com 9.9.9.9
```

---

##### Tool: [dig](<https://en.wikipedia.org/wiki/Dig_(command)>)

###### Resolves the domain name (short output)

```bash
dig google.com +short
```

###### Lookup NS record for specific domain

```bash
dig @9.9.9.9 google.com NS
```

###### Query only answer section

```bash
dig google.com +nocomments +noquestion +noauthority +noadditional +nostats
```

###### Query ALL DNS Records

```bash
dig google.com ANY +noall +answer
```

###### DNS Reverse Look-up

```bash
dig -x 172.217.16.14 +short
```

---

##### Tool: [certbot](https://certbot.eff.org/)

###### Generate multidomain certificate

```bash
certbot certonly -d example.com -d www.example.com
```

###### Generate wildcard certificate

```bash
certbot certonly --manual --preferred-challenges=dns -d example.com -d *.example.com
```

###### Generate certificate with 4096 bit private key

```bash
certbot certonly -d example.com -d www.example.com --rsa-key-size 4096
```

---

##### Tool: [network-other](https://github.com/trimstray/the-book-of-secret-knowledge#tool-network-other)

###### Get all subnets for specific AS (Autonomous system)

```bash
AS="AS32934"
whois -h whois.radb.net -- "-i origin ${AS}" | \
grep "^route:" | \
cut -d ":" -f2 | \
sed -e 's/^[ \t]//' | \
sort -n -t . -k 1,1 -k 2,2 -k 3,3 -k 4,4 | \
cut -d ":" -f2 | \
sed -e 's/^[ \t]/allow /' | \
sed 's/$/;/' | \
sed 's/allow  */subnet -> /g'
```

###### Resolves domain name from dns.google.com with curl and jq

```bash
_dname="google.com" ; curl -s "https://dns.google.com/resolve?name=${_dname}&type=A" | jq .
```

##### Tool: [git](https://git-scm.com/)

###### Log alias for a decent view of your repo

```bash
# 1)
git log --oneline --decorate --graph --all

# 2)
git log --graph \
--pretty=format:'%Cred%h%Creset -%C(yellow)%d%Creset %s %Cgreen(%cr) %C(bold blue)<%an>%Creset' \
--abbrev-commit
```

---

##### Tool: [python](https://www.python.org/)

###### Static HTTP web server

```bash
# Python 3.x
python3 -m http.server 8000 --bind 127.0.0.1

# Python 2.x
python -m SimpleHTTPServer 8000
```

###### Static HTTP web server with SSL support

```bash
# Python 3.x
from http.server import HTTPServer, BaseHTTPRequestHandler
import ssl

httpd = HTTPServer(('localhost', 4443), BaseHTTPRequestHandler)

httpd.socket = ssl.wrap_socket (httpd.socket,
        keyfile="path/to/key.pem",
        certfile='path/to/cert.pem', server_side=True)

httpd.serve_forever()

# Python 2.x
import BaseHTTPServer, SimpleHTTPServer
import ssl

httpd = BaseHTTPServer.HTTPServer(('localhost', 4443),
        SimpleHTTPServer.SimpleHTTPRequestHandler)

httpd.socket = ssl.wrap_socket (httpd.socket,
        keyfile="path/tp/key.pem",
        certfile='path/to/cert.pem', server_side=True)

httpd.serve_forever()
```

###### Encode base64

```bash
python -m base64 -e <<< "sample string"
```

###### Decode base64

```bash
python -m base64 -d <<< "dGhpcyBpcyBlbmNvZGVkCg=="
```

##### Tool: [awk](http://www.grymoire.com/Unix/Awk.html)

###### Search for matching lines

```bash
# egrep foo
awk '/foo/' filename
```

###### Search non matching lines

```bash
# egrep -v foo
awk '!/foo/' filename
```

###### Print matching lines with numbers

```bash
# egrep -n foo
awk '/foo/{print FNR,$0}' filename
```

###### Print the last column

```bash
awk '{print $NF}' filename
```

###### Find all the lines longer than 80 characters

```bash
awk 'length($0)>80{print FNR,$0}' filename
```

###### Print only lines of less than 80 characters

```bash
awk 'length < 80' filename
```

###### Print double new lines a file

```bash
awk '1; { print "" }' filename
```

###### Print line numbers

```bash
awk '{ print FNR "\t" $0 }' filename
awk '{ printf("%5d : %s\n", NR, $0) }' filename   # in a fancy manner
```

###### Print line numbers for only non-blank lines

```bash
awk 'NF { $0=++a " :" $0 }; { print }' filename
```

###### Print the line and the next two (i=5) lines after the line matching regexp

```bash
awk '/foo/{i=5+1;}{if(i){i--; print;}}' filename
```

###### Print the lines starting at the line matching 'server {' until the line matching '}'

```bash
awk '/server {/,/}/' filename
```

###### Print multiple columns with separators

```bash
awk -F' ' '{print "ip:\t" $2 "\n port:\t" $3' filename
```

###### Remove empty lines

```bash
awk 'NF > 0' filename

# alternative:
awk NF filename
```

###### Delete trailing white space (spaces, tabs)

```bash
awk '{sub(/[ \t]*$/, "");print}' filename
```

###### Delete leading white space

```bash
awk '{sub(/^[ \t]+/, ""); print}' filename
```

###### Remove duplicate consecutive lines

```bash
# uniq
awk 'a !~ $0{print}; {a=$0}' filename
```

###### Remove duplicate entries in a file without sorting

```bash
awk '!x[$0]++' filename
```

###### Exclude multiple columns

```bash
awk '{$1=$3=""}1' filename
```

###### Substitute foo for bar on lines matching regexp

```bash
awk '/regexp/{gsub(/foo/, "bar")};{print}' filename
```

###### Add some characters at the beginning of matching lines

```bash
awk '/regexp/{sub(/^/, "++++"); print;next;}{print}' filename
```

###### Get the last hour of Apache logs

```bash
awk '/'$(date -d "1 hours ago" "+%d\\/%b\\/%Y:%H:%M")'/,/'$(date "+%d\\/%b\\/%Y:%H:%M")'/ { print $0 }' \
/var/log/httpd/access_log
```

---

##### Tool: [sed](http://www.grymoire.com/Unix/Sed.html)

###### Print a specific line from a file

```bash
sed -n 10p /path/to/file
```

###### Remove a specific line from a file

```bash
sed -i 10d /path/to/file
# alternative (BSD): sed -i'' 10d /path/to/file
```

###### Remove a range of lines from a file

```bash
sed -i <file> -re '<start>,<end>d'
```

###### Replace newline(s) with a space

```bash
sed ':a;N;$!ba;s/\n/ /g' /path/to/file

# cross-platform compatible syntax:
sed -e ':a' -e 'N' -e '$!ba' -e 's/\n/ /g' /path/to/file
```

- `:a` create a label `a`
- `N` append the next line to the pattern space
- `$!` if not the last line, ba branch (go to) label `a`
- `s` substitute, `/\n/` regex for new line, `/ /` by a space, `/g` global match (as many times as it can)

Alternatives:

```bash
# perl version (sed-like speed):
perl -p -e 's/\n/ /' /path/to/file

# bash version (slow):
while read line ; do printf "%s" "$line " ; done < file
```

###### Delete string +N next lines

```bash
sed '/start/,+4d' /path/to/file
```

---

##### Tool: [grep](http://www.grymoire.com/Unix/Grep.html)

###### Search for a "pattern" inside all files in the current directory

```bash
grep -rn "pattern"
grep -RnisI "pattern" *
fgrep "pattern" * -R
```

###### Show only for multiple patterns

```bash
grep 'INFO*'\''WARN' filename
grep 'INFO\|WARN' filename
grep -e INFO -e WARN filename
grep -E '(INFO|WARN)' filename
egrep "INFO|WARN" filename
```

###### Except multiple patterns

```bash
grep -vE '(error|critical|warning)' filename
```

###### Show data from file without comments

```bash
grep -v ^[[:space:]]*# filename
```

###### Show data from file without comments and new lines

```bash
egrep -v '#|^$' filename
```

###### Show strings with a dash/hyphen

```bash
grep -e -- filename
grep -- -- filename
grep "\-\-" filename
```

###### Remove blank lines from a file and save output to new file

```bash
grep . filename > newfilename
```

##### Tool: [perl](https://www.perl.org/)

###### Search and replace (in place)

```bash
perl -i -pe's/SEARCH/REPLACE/' filename
```

###### Edit of `*.conf` files changing all foo to bar (and backup original)

```bash
perl -p -i.orig -e 's/\bfoo\b/bar/g' *.conf
```

###### Prints the first 20 lines from `*.conf` files

```bash
perl -pe 'exit if $. > 20' *.conf
```

###### Search lines 10 to 20

```bash
perl -ne 'print if 10 .. 20' filename
```

###### Delete first 10 lines (and backup original)

```bash
perl -i.orig -ne 'print unless 1 .. 10' filename
```

###### Delete all but lines between foo and bar (and backup original)

```bash
perl -i.orig -ne 'print unless /^foo$/ .. /^bar$/' filename
```

###### Reduce multiple blank lines to a single line

```bash
perl -p -i -00pe0 filename
```

###### Convert tabs to spaces (1t = 2sp)

```bash
perl -p -i -e 's/\t/  /g' filename
```

###### Read input from a file and report number of lines and characters

```bash
perl -lne '$i++; $in += length($_); END { print "$i lines, $in characters"; }' filename
```

#### Shell functions [<sup>[TOC]</sup>](#anger-table-of-contents)

##### Table of Contents

- [Domain resolve](#domain-resolve)
- [Get ASN](#get-asn)

###### Domain resolve

```bash
# Dependencies:
#   - curl
#   - jq

function DomainResolve() {

  local _host="$1"

  local _curl_base="curl --request GET"
  local _timeout="15"

  _host_ip=$($_curl_base -ks -m "$_timeout" "https://dns.google.com/resolve?name=${_host}&type=A" | \
  jq '.Answer[0].data' | tr -d "\"" 2>/dev/null)

  if [[ -z "$_host_ip" ]] || [[ "$_host_ip" == "null" ]] ; then

    echo -en "Unsuccessful domain name resolution.\\n"

  else

    echo -en "$_host > $_host_ip\\n"

  fi

}
```

Example:

```bash
shell> DomainResolve nmap.org
nmap.org > 45.33.49.119

shell> DomainResolve nmap.org
Unsuccessful domain name resolution.
```

###### Get ASN

```bash
# Dependencies:
#   - curl

function GetASN() {

  local _ip="$1"

  local _curl_base="curl --request GET"
  local _timeout="15"

  _asn=$($_curl_base -ks -m "$_timeout" "http://ip-api.com/line/${_ip}?fields=as")

  _state=$(echo $?)

  if [[ -z "$_ip" ]] || [[ "$_ip" == "null" ]] || [[ "$_state" -ne 0 ]]; then

    echo -en "Unsuccessful ASN gathering.\\n"

  else

    echo -en "$_ip > $_asn\\n"

  fi

}
```

Example:

```bash
shell> GetASN 1.1.1.1
1.1.1.1 > AS13335 Cloudflare, Inc.

shell> GetASN 0.0.0.0
Unsuccessful ASN gathering.
```