I’ve spoken about anti-virus scams previously but there is a specific example out on the net right now known as Anti-Virus-1.
Whilst it is not particularly widespread, there are still a growing number of fake product reviews around which attempt to lure the unsuspecting into buying the rogue security applications.
Anti-Virus-1 is just one of many fake products which seem to offer protection against online nasties whilst actually installing those very same threats onto the host machine.
As ever, it pays to do your homework before buying anything online.
Personally, I would recommend a more well-known brand, such as AVG, Norton, Panda or McAfee.