HOLD YOUR HORSES!!!! WOAH!
Have any of you thought about the most blindly obvious thing it could be? Windows Defender - it's still in Beta ain't it? It could be a false positive. And Spyware Doctor, even though it is supposedly "the best" is very rarely recommended above ad-aware and (the appalling in my opinion) Spybot SD.
The Hijackthis log looks okay, the HKLM key isn't there, he's checked for the sony rootkit, it probably isn't any other rootkit. No other virus killer or spyware detector is even seeing it. I would say it is a false positive and the virus isn't really there.