Hydey Hi.
Sounds like a virus or worm, AVG has a fix for this problem already, Download
& Update the program BEFORE scanning.
http://www.grisoft.com(good free AVG)
http://www.ewido.com(>>now called AVG Anti Spyware<< free 30 day trial -the best in my opinion)
Check your system using any of these programs (I reckon using all of them):
http://www.lavasoftusa.com/software/adaware/(free)
http://www.ccleaner.com/download/(free)
Spybot - Search & Destroy (FREE)
You can also read here point 4 in the post of LOTR....:
http://www.gnutellaforums.com/showthread.php?t=41432
Peace.