Try this;
SUPERAntiSpyware.com | Remove Malware | Remove Spyware - AntiMalware, AntiSpyware, AntiAdware!
Even if these programs don't find it, (Although they should, unless it is some new variation), it is invariably a file which directs you to spurious "security" sites, "Scareware", and similar.
If you can find the file on your machine, then just delete it.
The only other permanent cure is a clean install of Windows.
Regards....Mike Connor