Malware authors have produced a virus which poses as a test version the latest, as yet unreleased, version of MSN Messenger. The Virkel-F masquerades as "MSN Messenger 8 Working BETA" and is available from a bogus site as a supposedly leaked early version of the software.

Windows users who download and run the malware (given the name BETA8WEBINSTALL.EXE by hackers) will fail to get the promised chat client. Instead their existing MSN Messenger client will start to send download links to everyone in their contact lists in a bid to encourage others to become infected. Infected machines will also become clients in a botnet network of compromised PCs.

The social engineering trick uses interest in test version of Windows Live Messenger 8 – access to which is being auctioned on eBay - to hook victims. Anti-virus firm F-Secure has more on the Virkel-F threat here. ®