I went in to look at my profile and got a Drivecleaner pop-up. I am familiar with it because there was a problem a month or two ago at another website that I frequent.
The pop-up offers to download some kind of antivirus (well anti-something) program. I'm not particularly experienced with or knowledgeable about this particular problem, but I understand that it is website based. An administrator ought to take a look at this.