Microsoft Teams With Law Enforcement, Disrupts ZeroAccess Botnet

Microsoft's Digital Crimes Unit last week said it has joined with the FBI and Europol to disrupt the ZeroAccess botnet, also known as Sirefef.

ZeroAccess, which targets all major search engines and browsers, has infected nearly 2 million computers all over the world and cost online advertisers upward of $2.7 million each month, Microsoft says in a blog about the botnet.

"ZeroAccess is responsible for hijacking search results and directing people to potentially dangerous websites that could install malware onto their computer, steal their personal information or fraudulently charge businesses for online advertisement clicks," the blog states. "ZeroAccess also commits click fraud."

Microsoft calls ZeroAccess "one of the most robust and durable botnets in operation today," infecting most computers via drive-by downloads from popular websites or via fake software licenses.

The software giant has attempted to take down several botnets in the past two years, but some of them have regenerated and are delivering malware again. For this reason, Microsoft no longer uses the term "takedown" in its anti-botnet initiatives.

"Because of the sophistication of the threat, Microsoft and its partners do not expect to fully eliminate the ZeroAccess botnet," the blog states. "However, we do expect this legal and technical action will significantly disrupt the botnet's operation by disrupting the cybercriminals' business model and forcing them to rebuild their criminal infrastructure, as well as preventing victims' computers from committing the fraudulent schemes."

Microsoft says it is informing users whose computers have been infected. The malware contains tools to prevent its removal, so the software giant is offering instructions on how to remediate the problem.

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