A handful of worms topped the list -- ArcServe, IMspread, QVOD, IRCBot, and Tiotua.
Akonix also notes a 12% rise in attacks over P2P networks.
While the increase in IM attacks is interesting, it's surprising to me -- considering how much sewage transverses P2P networks -- that there's any room for growth at all in those file sharing networks. The risk is minimal for corporations that have deployed closed instant messaging and collaborative systems. Most, if not all, of these worms target the public IM networks such as AIM, Yahoo, and GoogleTalk. But I wouldn't be quick to connect corporate systems to these public networks.
It's my understanding that most of these threats travel like e-mail worms and users have to click to get infected. So common sense is all that's needed to keep most systems clean: do not to accept messages from screen names you're not familiar with and never, never-ever, accept links from strangers.
A quick look at the list of IM threats uncovered this year, available at the Akonix Web site, lets you see that the vast majority are ranked as low risk.
Aside from banning public IM networks, how does your company protect itself from IM threats?