How Hackers Use Your IP Address to Hack Your Computer & How to Stop It « Null Byte :: WonderHowTo

Your IP (InternetProtocol) address is your unique ID on the internet. It's synonymous with your home address. Anyone in the world can contact your computer through its IP address, and send a retrieve information with it.I'm sure at one time or another you've heard that hackers can hack your computer via your IP address. This is one of the reasons proxies and anonymity services exist, to protect people from learning your IP address. So how are hackers using just an address to get into your computer and make your life hell?Open ports. Your computer runs services like media sharing on what are calledports. A port is just an opening that a service uses as a communications endpoint. There are 65,535 total allocated ports inTCP/UDP. To exploit a service on a port, a hacker wouldbanner grabfor the software and version. After they learn that information, they would search sites likePacket Stormfor known exploits to run against the service.Today'sNull Byteis going to demonstrate a simple "port scan" on local computer using Nmap, and teach how a hacker would exploit these services, as well as how to guard ourselves against it. This will be done under Linux, but Nmap is available for all platforms. If you can't figure out how to install it in Windows with the GUI installer (yeah, right), follow along usingCygwin.Step1Download & Install NmapBold words are commands that must be entered in a terminal emulator.First, we must download Nmap, which is going to be our tool that we use for port scanning and information gathering:wget http://nmap.org/dist/nmap-5.51.tar.bz2Now, extract the archive:tar -zxvf nmap-5.51.tar.bz2Change to the newly made directory:cd <directory name>This is the standard installation procedure:./configuremake && sudo make installNmap should now be installed!Step2Scan for a TargetLet's scan a local computer. I'm going to use a website as an example, rather than a local computer. This is because my firewall is absolutely crazy, and filters out scans. Don't scan a remote computer with the intentions of doing bad deeds. This is for educational purposes only.Start by mapping out your local network:sudo nmap -sP 192.168.1.0/24That should return a list of hosts that are up for a port scan!Step3Scan Your Individual TargetOut of the returned list of targets, pick one that you would like to scan for services. Let's do a full scan of all the TCP/UDP ports:sudo nmap -p 1-65535 -T4 -A -v <target IP goes here>You should get something that looks like the following image:As you can see, this target has MANY open ports. SSH piques my interest, so let's move on to banner grabbing to learn the software version or our choice of service.Step4Banner GrabbingFor this, you can use the regular ol'telnetclient. Telnet comes with Windows and most Linux distros:telnet <host IP> <port banner to grab>From this, I would learn which software version the service is running, then see if I can find a way to exploit it.How Can I Protect Myself?Luck for all of you lovely people, I recently made atutorial on iptables, which will filter out unwanted connections. Also, disable any unnecessary programs that connect to the internet (remote administration, media sharing, etc).Windows users, installComodo firewall, it's incredible and uses a simple point and click installation, and will filter portsforyou. It has great default settings and it isfree.Want to start making money as a white hat hacker?Jump-start your hacking career with our2020 Premium Ethical Hacking Certification Training Bundlefrom the newNull Byte Shopand get over 60 hours of training from cybersecurity professionals.Buy Now (90% off) >Other worthwhile deals to check out:97% off The Ultimate 2021 White Hat Hacker Certification Bundle99% off The 2021 All-in-One Data Scientist Mega Bundle98% off The 2021 Premium Learn To Code Certification Bundle62% off MindMaster Mind Mapping Software: Perpetual LicensePhoto bypowtacRelatedHacker Fundamentals:The Everyman's Guide to How Network Packets Are Routed Across the WebHacker Fundamentals:A Tale of Two StandardsHack Like a Pro:Networking Basics for the Aspiring Hacker, Part 1Hack Like a Pro:How to Exploit and Gain Remote Access to PCs Running Windows XPHack Like a Pro:Linux Basics for the Aspiring Hacker, Part 6 (Networking Basics)How To:Hack Your Firefox User Agent to Spoof Your OS and BrowserHow To:The Five Phases of HackingHow To:Use & Abuse the Address Resolution Protocol (ARP) to Locate Hosts on a NetworkHack Like a Pro:How to Scan the Globe for Vulnerable Ports & ServicesHow To:Understand & Use IPv4 to Navigate a NetworkAdvice from a Real Hacker:Why I'm Skeptical That North Korea Hacked SonyHack Like a Pro:How to Cover Your Tracks So You Aren't DetectedHack Like a Pro:How to Save the World from Nuclear AnnihilationHack Like a Pro:Abusing DNS for ReconnaissanceHack Like a Pro:How to Remotely Grab Encrypted Passwords from a Compromised ComputerRasberry Pi:Connecting on ComputerHacker Fundamentals:A Gentle Introduction to How IP Addresses WorkHow To:Assign a Static IP Address in Windows 7How To:Bypass a Local Network Proxy for Free InternetHow To:Make a Change-of-IP Notifier in PythonMastering Security, Part 2:How to Create a Home VPN TunnelNews:Student Sentenced to 8mo. in Jail for Hacking FacebookHow To:Spy on the Web Traffic for Any Computers on Your Network: An Intro to ARP PoisoningHow To:Turn Your House Lights On & Off Using the InternetHow To:Hack Wireless Router Passwords & Networks Using HydraHow To:Run a Free Web Server From Home on Windows or Linux with ApacheHacking in the Media:Our Craft's Portrayal as Black MagicHow To:Chain Proxies to Mask Your IP Address and Remain Anonymous on the Web