Remote Access Trojan.
It's worse then a virus, trojan, and worm. It's called the Black Orifice created by the Cult of the Dead Cow. You can find out if you have this by searching for ".RAT" using advanced search options on your computer. If you have it, your screwed because now you don't have your computer...your borrowing it.
Say hi to the hacker that's watching you that gave you the RAT.