So I was playing Fallout: New Vegas, using the steam overlay browser looking through fallout.wikia.com for stuff, when one page redirected to one of those scuzzy "your computer might have dangerous files on it! Scan now? yes/no" popups. Of course I couldn't close the window normally so I just killed the gameoverlay process, but I had my virus scanner off (because I was playing a game), so now instead of playing F:NV I'm running my virus scanner. Hopefully I didn't contract anything, but argh. So, lesson learned. Don't browse anything through the steam overlay browser with your virus scan turned off, even normally innocuous sites. And maybe stay off of wikia for a few days while they sort this out.
Also, web developers? Any time I go somewhere in firefox and see "please turn off adblock so my 3 kids won't starve to death"? This shit is why it'll never happen.
EDIT: Avast! quick scan didn't find anything. I'd do a full scan, but I had the good sense to kill the browser process instead of actually clicking on "no" and I'm not even sure it was redirecting me to a virus in the first place, so I'm gonna call it good. Still, fuck this shit.