The best thing to do is to scan your computer with your anti virus program. If you dont have one get avast its free for home use (i think). You can also just use
this it should tell you if you have it or not. i know its simple but if you want an explination on why it works i could provide you with an article. Also theres a very god chance you dont have it most of the people who get it are people who download and install random crap or click on every pop-up there is.