I have had two of my office computers get hit by this in the past year. At first I thought the office assistant was going to sites that she shouldn't have, unti

I have had two of my office computers get hit by this in the past year. At first I thought the office assistant was going to sites that she shouldn't have, until I got hit by it while on Autoblog.com which is an AOL site. At that point noscript and adblock got installed. But there are definitely badthings coming from ad networks. They are subtle - it may only try to send the payload every 10 or 20 screen refreshes - but they do send it. It took 10 screen refreshes on Autoblog, for example. This was some months ago, so I don't know if there is still a problem. The payload for me was the real looking Windows box that pops up and tells you that you have 20 viruses and to fix it just send $29.95 to this site and it will all go away.