Buon sniffing...
AIM Sniff is a utility for monitoring and archiving
AIM and MSN messages across a network. It can be used to monitor for cases of
harassment or warez trading. It has the ability to do a live dump (actively
sniff the network) or read a PCAP file and parse the file for IM messages. You
also have the option of dumping the information to a MySQL database or STDOUT.
AIM Sniff will also monitor for an IM login and then perform an SMB lookup on
the originating computer in order to match NT Domain names with IM login names
(handles). MSN sniffing support was added. The code was modularized for ease
of contribution and protocol development.http://freshmeat.net/projects/aimsniff
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Fonte: Security/Forensic Tool: AIM Sniff