Trend Micro threat analysts recently snagged an email pushing a bogus Windows Live Messenger residing in http://{BLOCKED}s-live-msn.serveftp.com/Windows_Live_9.0_beta.exe (detected as WORM_VB.PAB). The .EXE file is, of course, not the “real” Windows Live Messenger but a bot that reports to an IRC-based C&C with the following details about the infected system:

The said bot’s primary function seems to be MSN spamming. As of this writing, the C&C channel is currently idle, as it has not yet issued commands. Apart from MSN spamming, the said bot was also designed to spread via USB autorun and P2P networks like Kazaa and Limewire.

Windows Live Messenger users should thus refrain from clicking the malicious URL spreading via email to avoid infection. Trend Micro Smart Protection Network already blocks the malicious URL and detects the fake Windows Live Messenger as WORM_VB.PAB.