With 15% of all malware now identified as fake anti-virus scan scams and growing, it's more clear than ever that the crooks have found market niche that's not only filled with targets, but also may be self-reinforcing.Whatever you think about how well- or ill-informed average users are when it comes to matters of security, it's obvious that the malware-makers are betting (successfully) that users know enough to be scared if malware but not enough to recognize a malware scam when it comes at them.

That's the almost unavoidable conclusion drawn from a recently released Google study showing that anti-virus scareware scams make up 15% of malware, and are responsible for fully half of the ad-delivered malware. Calling the effectiveness of the tactic a Nocebo Effect (the opposite of placebo), Google researchers found scareware growing from 3% of infected sites to 15% in just over a year.

In a blog posting, Google security researcher Niels Provos did note that "the lifespan of domains distributing Fake AV attacks has decreased significantly."

The phenomenon is self-fertilizing: the more worried users become about whether or not their computers are secure, the likelier a percentage of them are to respond to scareware subscription requests. As Google's researchers put it:

"As users are becoming increasingly aware of the need to secure their computers, attackers have been leveraging this awareness by employing social engineering techniques to distribute Fake AV software."

Which puts the onus back on you and your security team to educate your company's users, remind them that no legit security company pops up come-ons and scare-ads, and that if they have any security questions, issues or concerns, they should bring them to your attention, rather than paying a crook to (not) fix them.