I just fell for that one as well its a real pain.  Just fininshed reinstalling my computer from scratch.  Even more anoying is I don't know where I picked it up from.  I'm security mad with up to date antivirus, a fire wall the lot but it still got me. 

By the way you'll know if you've got it because just about ever exe file on the computer gets trashed.

the only positive i can find in this is that i was about due for a clean install anyway as windows was playing up and i kept putting it off, this forced my hand. 

Also a chance to organise my poser runtimes better!