DSniff
dSniff is a set of password sniffing and network traffic analysis tools written by security researcher and startup founder Dug Song to parse different application protocols and extract relevant information. dsniff, filesnarf, mailsnarf, msgsnarf, urlsnarf, and webspy passively monitor a network for interesting data (passwords, e-mail, files, etc.). arpspoof, dnsspoof, and macof facilitate the interception of network traffic normally unavailable to an attacker (e.g., due to layer-2 switching). sshmitm and webmitm implement active man-in-the-middle attacks against redirected SSH and HTTPS sessions by exploiting weak bindings in ad-hoc PKI. Overview. The applications sniff usernames and  passwords, web pages being visited, contents of an email, etc. As the name implies, dsniff is a network sniffer, but it can also be used to disrupt the normal behavior of switched networks and cause network traffic from other hosts on the same network segment to be visible, not just traffic involving the host dsniff is running on. It handles FTP, Telnet, SMTP, HTTP, POP, poppass, NNTP, IMAP, SNMP, LDAP, Rlogin, RIP, OSPF, PPTP MS-CHAP, NFS, VRRP, YP/NIS, SOCKS, X11, CVS, IRC, AIM, ICQ, Napster, PostgreSQL, Meeting Maker, Citrix ICA, Symantec pc Anywhere, NAI Sniffer, Microsoft SMB, Oracle  SQL*Net, Sybase and Microsoft SQL protocols. The name "dsniff" refers both to the package as well as an included tool. The "dsniff" tool decodes passwords sent in cleartext across a switched or unswitched Ethernet network. Its man page explains that Dug Song wrote dsniff with "honest intentions - to audit my own network, and to demonstrate the insecurity of cleartext network protocols." He then requests, "Please do not abuse this software." These are the files that are configured in dsniff folder /etc/dsniff/ The man page for dsniff explains all the flags. To learn more about using dsniff, you can explore  the Linux man page. This is a list of descriptions for the various dsniff programs. This text belong to the dsniff “README” written by the author, Dug Song.