Yahoo, Fox and Google Inadvertently Spread Malware through Ads

yahoo fox and google inadvertently spread malware through ads jsprontexti outbreakInternet security software and common sense can steer you away from the some of the Web’s skeeviest destinations to avoid malware, but when it’s embedded in ads from some of the biggest advertising networks out there, you may be looking at infection at every turn.

According to Avast, a manufacturer of antivirus software, major ad networks affiliated with Yahoo, Fox and Google have been distributing “poisoned ads” containing malicious code. The so-called JS:Prontexi attack uses JavaScript that can open the door to malware attacks and zero-day exploits, all without clicking on anything.

Because the infected networks serve more than 50 percent of all online advertising, poisoned ads have appeared on major sites including The New York Times, TechCrunch and Drudge Report.

This isn’t the only outbreak of a computer virus spread through advertising. “The poison ad infiltration method is growing in popularity because it does not require users to click on anything,” said Avast virus analyst Jiri Sejtko, in a statement. “Users can get infected just by reading their favorite newspaper or by doing a search on popular topics; the infection begins just after the poisoned ad is loaded by the browser.”