Microsoft Files Five Lawsuits over "Malvertising"

In a bid to fight a growing problem, Microsoft announced that it has filed five lawsuits over online ads infected with malicious code.

In the past, Microsoft has attempted to work with online ad networks to prevent such "malvertising.”  This is the first time it has gone to court.  The businesses that Microsoft is going after, it says, used popular online ad platforms to hide malicious code and try to infect unsuspecting users.  If a user follows a link presented in the ad, he could end up with damaged data or stolen information, or even find his PC under someone else's control (a so-called zombie computer).

"Our filings in King County Superior Court in Seattle outline how we believe the defendants operated, but in general, malvertising works by camouflaging malicious code as harmless online advertisements," Microsoft Associate General Counsel Tim Cranton said in a blog posting.  "Although we don't yet know the names of the specific individuals behind these acts, we are filing these cases to help uncover the people responsible and prevent them from continuing their exploits," Cranton said.

Cranton compared the most recent lawsuits to legal action that Microsoft has taken in the past against those suspected of click fraud or instant messaging spam.

"This work is vitally important because online advertising helps keep the Internet up and running," Cranton said.  "It's the fuel that drives search technologies.  It pays for free online services like Windows Live, Facebook, Yahoo, and MSN.  Fraud and malicious abuse of online ad platforms are therefore a serious threat to the industry and for all consumers and businesses that rely on these free services."

Why it matters:  Online scammers never really go away, they just change their tactics. They pose a serious problem for companies and Internet marketers because they make consumers suspicious of all ads, even legitimate ones.  The government has limited resources to fight these scammers, and Microsoft has used private lawsuits to help bolster government efforts.