I've had that one hit me a few times. The IT guys warned me that the newest game in town is to hijack a link on Yahoo or Google home pages. You hit the link, and you get where you wanted to go, but also pick up a present along the way. My last one came from a hijacked Sports Illustrated link. It was a fun one. Not only did I get the security warnings and threats, with the "must buy our protection" pop ups, I then started with the hardcore p0rn pop-ups to make me want to buy the protection. Malwarebytes did the trick. Although, I'm dealing with a new one now. It's a new one, which is avoiding all of the detectors (Ad-aware, malwarebuytes, etc.). Although, this one is pretty lame. If I use a search engine, and click on a link I get as a result, it re-directs me to somewhere else, most often a company offering domain registry, items for sale, or (I love this one) the FBI home page.