Since you have webroot and didn't see it, than your problem is not the same as mine was. Mine was spygraphica.
To clarify my situation, according to the sources on google, spygraphica on my pc is installed by someone who has access to my pc. I'm not sure if that was the case for me... my other thread asks the question where I could have gotten it over the internet.
Once again, your situation is different so my comments don't apply.