Image by World's Saddest Man via FlickrSadly, this is one of the better scams out there for parting inexperienced computer users from their money. I know people who have made this "purchase", only to find out when they called me that it is completely bogus.
This malware, that claims to be a legitimate anti-virus or anti-spyware application literally takes over the user's computer, making it impossible to use, with pop-ups occurring every few seconds warning of all the infections the rogue software has detected on the user's computer.
Depending on the particular infection, the solution is as simple as doing a windows restore to a time before you got the rogue ware, to some that are extremely difficult to remove.
One of the better tools for removing this type of spyware that I have found is SuperAntiSpyware Pro. It is available as a 30 day trial.
Here is the full article on this lucrative scam:
Fake Security Software Steals $34 Million Monthly -- InformationWeek: "Fake Security Software Steals $34 Million Monthly"