Well that is bizarre. The only thing that's ever connected via USB is a printer and a wireless mouse. Other than that, the only removable memory that's ever been inserted is a memory card for a digital camera. I don't see picture or avi files being infected truly. If there's anything else you need me to do just let me know. I'm providing a link to you guys through my website http://www.tonguetacos.com. Not a lot of traffic, but I always sing your praises.