From the sounds of things, it would appear that you (or someone using your computer) may have clicked on a link or ad of some sort that wasn't what it claimed to be, or that they did not know that they were being re-directed to a malware site. My recommendation would be to try running a scan with SpyBot Search & Destroy, which you can find online at www.safer-networking.org I think this should help to cleans any remnant that you may find of such things. Also, I suggest running an in-depth registry scan with ccleaner after you are done with the SpyBot just to make sure that you haven't opened up any other potential registry issues by removing some of the other references to these things that SpyBot does not detect automatically. This generally will come up in your MUIcache, given the way that the system registry works.

Thanks to pointing out what I preach since ages! Just a short remark: You get [desc=Seed Bonus point]SBP[/desc] for just seeding, not for a torrent. You do not get more SBP for seeding several torrents at once (like the often asked question: I seeded 20[0…] torrents at a time, why don't I get more SBP?). The SBP do only count for your seeding time, regardless of the # of torrents you seed!