Loans Unlimited

Every time I open a website on the Mozilla Firefox Browser the Loans Unlimited site pops up. I don't know how it has attached itself to the sites I use because I've never needed a loan nor searched the web for a loan.<br> <br> All I can assume is that there is Spyware or Malware that has attached itself to the Firefox Browser. I don't know how to get rid of the pop-up (which is infuriating because I'm paying for the download each time). If I'm quick enough I can stop it just as it starts to download.<br> <br> I wonder if this has happens to anybody else?