The ads served by Bing and Google along with your search results are linking more and more often to sites trying to infect your machine.

Neither Bing nor Google effectively prescreens these bogus advertisers, so it's up to us to detect and avoid them.

You may recently have used either Google or Microsoft's new Bing search engine to find the popular Malwarebytes Anti-Malware utility. If so, chances are good that the sponsored ads alongside your search results contained links to the very malware that the security tool is designed to remove.

The three largest search sites — Google, Yahoo, and Bing — regularly sell security-related keywords to criminals looking to trick you into downloading and installing fake anti-malware products. The crooks then steal your personal information or hold your system for ransom before letting you remove their malware from your machine.

The search providers have been aware of this for years. To their discredit, they've done little to end the practice, even though it's in their power to do so. The reason? They're making money hand over fist from those sponsored text ads and don't want to kill the goose that lays the golden eggs.

Case in point: A Windows Secrets reader searched Bing for Malwarebytes Anti-Malware. He clicked the first link displayed and ended up on a site that installed a rogue antivirus program on his PC. (See Figure 1.)

Figure 1. Malicious sponsored ads are interspersed with links to legitimate companies when you query search engines for the Malwarebytes security program.

Rather than getting a tool to clean up a friend's infected computer, this Web surfer ended up having to disinfect his own. He and several other people I've heard from recently were hit with the result of search services' selling sponsored links without validating those links' legitimacy.

As search terms become popular, scammers jump at the chance to have their bogus ads appear among the results. To get their deceptive ads into these highly visible search results, these criminals simply buy these high-traffic terms from the search engines.

Source: Windows Secrets Newsletter • Issue 217 • 2009-10-08