Here's an excellent article from MIT's Technology Online about malware and the companies that make it.   

" Not long after Prince William and Kate Middleton exchanged vows on April 29, a 1981 wedding portrait of the groom's late mother, Princess Diana, appeared as one of the top three images for people typing the most popular search term on Google that morning: "royal wedding coverage." But the link was a trip wire. Fraud artists had finagled a malicious website through Google's algorithm. The link led to a hacked page on a Web comic book called Kiwiblitz.com, which redirected the browser to another site—one with a domain name from an obscure Australian island territory and hosted in Sweden. That site displayed a realistic-looking program called "XP Anti-Spyware" that issued bogus warnings—Your Computer Is Infected! A few clicks led to a purported solution, for $59.95: a download of a fix that didn't actually exist.

Chalk up another success for what's generally known as the "fake antivirus" scam. Federal investigators and security experts estimate that its various iterations have extracted at least $1 billion from victims in the past several years,..."