Yeah, have you run any virus scans lately? If you don't have one, try
http://housecall.trendmicro.com/ It's online, and free. Works pretty OK as well. You
We were testing a computer at work on a wide open DSL line, and within a day it was infested. Ran it through there and just by having the thing turned on and on the network with no protection it was able to pick up ~4 different virus'.
Edit: of course, with what was on that system, we had to end task on pretty much everything just to be able to load the page. I think we also had to edit the hosts file