Just out of interest as you've now solved the problem, I had a computer a few years ago that got the Netsky worm. In fact this is a series of worms that keeps cropping up so it would seem, not aided by the fact that some helpful soul made the code available to create it on the internet - the sorcerer's apprentice - in the end I got rid of it my finding out where it snuck its files, finding them and deleting them