Sophos offers a detailed report related to FAKEAV attacks
Sophos – Research report on What is Fake AV?
QUOTE: Fake AV, or Fake Anti-Virus, is one of the most frequently-encountered and persistent threats on the web. This malware, with over half a million variants, uses social engineering to lure users onto infected websites with a technique called blackhat Search Engine Optimization. Once the Fake AV is downloaded onto the user’s computer, the software will scare them into believing their system is infected with threats that do not really exist, and then push users to purchase services to clean up the non-existent threats. The Fake AV will continue to send these annoying and intrusive alerts until a payment is made.