Google Finds Fake AV Operations Grow on Back of SEO, Malicious Ads

New research from Google is shining a light on just how prevalent rogue antivirus scams have become.

According to a paper presented April 27 at the Usenix Workshop on Large-Scale Exploits and Emergent Threats, in San Jose, Calif., fake antivirus programs now account for 15 percent of all the malware Google detects on the Web. In an analysis of 240 million Web pages between January 2009 and February 2010, Google detected more than 11,000 domains involved in rogue antivirus operations.

"Social engineering attacks scaring users about false insecurities are not new," the report noted. "As early as 2003, malware authors prompted users to download fake AV software by sending messages via a vulnerability in the Microsoft Messenger Service … More recent fake AV sites have evolved to use complex JavaScript to mimic the look and feel of the Windows user interface. In some cases, the fake AV detects even the operating system version running on the target machine and adjusts its interface to match."

Google noticed an upward trend in the amount of fake antivirus software it encountered during the study each week. In the first of week of January 2009, the researchers encountered 93 unique rogue AV domains, while they found 587 domains in the last week of January 2010.

The researchers also discovered that fake AV domains have more landing domains funneling user traffic than other infection domains, and distributors rely heavily on online advertisements and domains with pages that contain trending keywords.

"We believe that fake AV domains have also evolved to use more agile distribution networks that continuously rotate among short-lived domains in an attempt to avoid detection," the report said.

Vincent Weafer, vice president of Symantec Security Response, told eWEEK that rogue security applications often make use of search engine optimization techniques, such as exploiting search engine indexing algorithms, link farming, keyword stuffing and cloaking.

"In most cases, rogue AV peddlers have automated the SEO poisoning process for speed of response," Weafer said. "They seem to pull terms from search engines and feed that data into their network of compromised Websites. The compromised sites are in fact just ordinary Websites run by regular people, but which unbeknownst to them have been compromised with malware. This malware lies below the surface and only shows its head to people that have been referred to the site from the poisoned search engine result, specifically as a result of using a hot trend key word."

The researchers' paper can be read here. (PDF)