Microsoft is working with the FBI to stop malware responsible for infecting more than 2 million computers as a part of an effort to steal dollars from online advertising companies.
The company's digital crime unit said on Friday it has "successfully disrupted" rampant malware called the Sirefef botnet — also known as ZeroAccess — which recently targeted search results on sites such as Google, Bing and Yahoo search engines.
See also: 14 Google Tools You Didn't Know Existed
ZeroAccess malware affects devices running Windows by hijacking search results and downloading malicious malware onto infected systems. It directed each of its almost two million infected computers to click on as many as 48 ads an hour, but even though it wasn't true human traffic, advertisers were paying fees for fake clicks. Microsoft said the attack is estimated to cost online advertisers $2.7 million each month.
"Today’s action is expected to significantly disrupt the botnet’s operation, increasing the cost and risk for cybercriminals to continue doing business and preventing victims’ computers from committing fraudulent schemes," Microsoft said in a statement.
In addition to teaming up with the FBI, Microsoft is also working with the agency's European counterpart European Cybercrime Centre (EC3).
The news comes just a few weeks after Microsoft unveiled its new Cybercrime Center, described in the video below:

In a press release, Microsoft cited research by the University of California, San Diego that showed 1.9 million computers were infected with ZeroAccess in October, and more than 800,000 ZeroAccess-infected computers are active on the Internet every day.
“If the hacker community has not yet taken notice, today’s disruption of the ZeroAccess botnet is another example of the power of public-private partnerships,” FBI Executive Assistant Director Richard McFeely said in a statement. “It demonstrates our commitment to expand coordination with companies like Microsoft and our foreign law enforcement partners — in this case, Europol — to shut down malicious cyberattacks and hold cybercriminals accountable for exploiting our citizens’ and businesses’ computers.”
Have something to add to this story? Share it in the comments.
Image: Adam Berry/Getty Images