Members of The Houston Linux Users Group
discovered that the newest sources of libpcap and tcpdump available from tcpdump.org were contaminated with trojan code. HLUG has notified the maintainers of tcpdump.org. See our reports here
Latest libpcap & tcpdump sources from tcpdump.org contain a trojan.
Libpcap provides a packet sniffing library for programs like Snort.
Tcpdump is a standard tool for packet sniffing.
The trojan contains modifications to the configure script and gencode.c (in libpcap only).
The configure script downloads http://mars.raketti.net/~mash/services
which is then sourced with the shell. It contains an embedded shell script that creates a C file, and compiles it.
The program connects to 188.8.131.52 (mars.raketti.net) on port 1963 and reads one of three one byte status codes:
A - program exits
D - forks and spawns a shell and does the needed file descriptor manipulation to redirect it to the existing connection to 184.108.40.206.
M - closes connection, sleeps 3600 seconds, and then reconnects
It's important to note that it reuses the same outgoing connection for the shell. This gets around firewalls that block incoming connections.
Gencode.c is modified to force libpcap to ignore packets to/from the backdoor program, hiding the backdoor program's traffic.
This is similar to the OpenSSH trojan a few months ago.
Many Mirrors are infected with the trojan!!!
Main Mirror Site (wiretapped.net) will no longer be providing tcpdump downloads until things are straightened out.