" ...IM bots are leveraging social engineering techniques to spread among users, most of whom are unaware that they are extending the bots' reach.
The most notable new threat is the IM.Myspace04.AIM worm. It attempts to convince AIM users to download malicious content. Once infected, the host acts as a bot by sending out new messages to infect others, plus responding blindly to messages it receives."
Sounds very similar to IRC bots (Like Darkbot) that have plagued chatrooms for years. Now the attack is targeted at AIM users, who may not be savy enough to recognize a bot. This bot also appears to be a bit smarter than your average AIM bot, using popular lingo like "lol thats cool". The bot presents you with a link to a web site that infects you with Malware.