Apparently a virus named Trojan.Peacomm is going wild over the net. And as far as I can tell, not many Anti Virus programs have a fix for it, especialy not the free ones.
Apparently it arrives in emails with news type topics or the standard Re: type topic. It has a file attached, that, when run, installs the virus.
Here's the full report, worth reeding through even if you don't have it yet.