IM to Spread Malware: the Butterfly Effect

This weekend, an unnamed worm forced Microsoft to temporarily suspend active links in Live Messenger 2009, in order to prevent the aggressive worm from spreading further. This is quite a surprising measure, because worms spreading through Instant Messaging (IM) such as Skype, Yahoo! Messenger and Microsoft Live Messenger are not new at all! For example, the AimVen worm was discovered in 2003 and was targeting the America Online Instant Messenger platform.

The modus operandi for this type of attack is simple:

1. the victim receives a message that contains an hyperlink from one of their contacts
2. the victim clicks on the hyperlink;
3. the victim gets infected.

More: http://blog.eset.com/2010/11/16/im-to-spread-malware-the-butterfly-effect