I should have mentioned that I thought it was the ad sever all along, not cheathappens itself. The last time I got a trojan virus was from another ad server at a different forum. In that case they were able to determine that the ad servers were indeed infected, but only for a short while, so I was just unlucky enough to hit the small time window. It also required that an older verion of Java JRE be installed. This happened about 2 years ago.