DSniff For Linux

The DSniff project is comprised of the following tools that aid network auditing and penetration testing: 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 monkey-in-the-middle attacks against redirected SSH and HTTPS sessions by exploiting weak bindings in ad-hoc PKI.

I wrote these tools with honest intentions - to audit my own network, and to demonstrate the insecurity of most network application protocols. Please do not abuse this software.

arpspoof

redirect packets from a target host (or all hosts) on the LAN intended for another local host by forging ARP replies. this is an extremely effective way of sniffing traffic on a switch. kernel IP forwarding (or a userland program which accomplishes the same, e.g. fragrouter :-) must be turned on ahead of time.

dnsspoof

forge replies to arbitrary DNS address / pointer queries on the LAN. this is useful in bypassing hostname-based access controls, or in implementing a variety of man-in-the-middle attacks (HTTP, HTTPS, SSH, Kerberos, etc).

dsniff

password sniffer. 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 pcAnywhere, NAI Sniffer, Microsoft SMB, Oracle SQL*Net, Sybase and Microsoft SQL auth info.

dsniff automatically detects and minimally parses each application protocol, only saving the interesting bits, and uses Berkeley DB as its output file format, only logging unique authentication attempts. full TCP/IP reassembly is provided by libnids(3) (likewise for the following tools as well).

filesnarf

saves selected files sniffed from NFS traffic in the current working directory.

macof

flood the local network with random MAC addresses (causing some switches to fail open in repeating mode, facilitating sniffing). a straight C port of the original Perl Net::RawIP macof program.

mailsnarf

a fast and easy way to violate the Electronic Communications Privacy Act of 1986 (18 USC 2701-2711), be careful. outputs selected messages sniffed from SMTP and POP traffic in Berkeley mbox format, suitable for offline browsing with your favorite mail reader (mail -f, pine, etc.).

msgsnarf

record selected messages from sniffed AOL Instant Messenger, ICQ 2000, IRC, and Yahoo! Messenger chat sessions.

sshmitm

SSH monkey-in-the-middle. proxies and sniffs SSH traffic redirected by dnsspoof(8), capturing SSH password logins, and optionally hijacking interactive sessions. only SSH protocol version 1 is (or ever will be) supported - this program is far too evil already.

tcpkill

kills specified in-progress TCP connections (useful for libnids-based applications which require a full TCP 3-whs for TCB creation).

tcpnice

slow down specified TCP connections via "active" traffic shaping. forges tiny TCP window advertisements, and optionally ICMP source quench replies.

urlsnarf

output selected URLs sniffed from HTTP traffic in CLF (Common Log Format, used by almost all web servers), suitable for offline post-processing with your favorite web log analysis tool (analog, wwwstat, etc.).

webmitm

HTTP / HTTPS monkey-in-the-middle. transparently proxies and sniffs web traffic redirected by dnsspoof(8), capturing most "secure" SSL-encrypted webmail logins and form submissions.

webspy

sends URLs sniffed from a client to your local Netscape browser for display, updated in real-time (as the target surfs, your browser surfs along with them, automagically). a fun party trick.