After my computer got a bit slow and started showing pop-ups I found this antivirus program called "Windows Protection Suite". It said I was infected and had to pay them to fix it. I didn't but afterwards I just got more annoying pop-ups.
Found this blog-post explaining I got (almost) scammed:
Got a free years subscrition via my bank for McAfee so I am using that, have a qick look for give aways like that, or I usually use AVG free, probably shouldn't mention that on a mcafee forum.