Luckily it hasn't infected my PC, but my antivirus software keeps stopping it from taking root.
It happened earlier this week, but I had some other windows open so I figured it was one of them. But then it happened twice again whilst browsing this site.
It appears that it is the Vundo or Virtumonde virus trying to do the dirty work. For those who may be in the same boat, it takes over your browser and randomly generates popups for various services from virus removal (lol) to online MMOs.
It exploits a security hole in older versions of java so if you haven't updated java in a while that should help. I wager that it's trying to piggyback in on one of the banner ads.
Anyone else having this happen?
Updated by Fox2K9