Microsoft Claims Another Botnet Takedown

After taking down the longstanding Rustock botnet earlier this year, Microsoft says it has taken down another troublesome network, the botnet known as Kelihos (Waledac 2.0).

In a blog posted Tuesday, Richard Boscovich, senior attorney for Microsoft's Digital Crimes Unit, said Kelihos was brought down in an operation, code-named "Operation b79," that used similar legal and technical measures as the company's previous botnet takedowns.

The takedown will be the first time Microsoft has named a defendant in one of its civil cases involving a botnet, Boscovich says.

"The Kelihos takedown is intended to send a strong message to those behind botnets that it’s unwise for them to simply try to update their code and rebuild a botnet once we’ve dismantled it," the blog says. "When Microsoft takes a botnet down, we intend to keep it down – and we will continue to take action to protect our customers and platforms and hold botherders accountable for their actions."

In the complaint, Microsoft alleges that Dominique Alexander Piatti, dotFREE Group SRO, and 22 unnamed actors operated and controlled the Kelihos botnet.

"Naming defendants in this case marks a big step forward for Microsoft in making good on its commitment to aggressively protect its platform and customers against abuse from whomever and wherever it may originate," the blog says. "Naming these defendants also helps expose how cybercrime is enabled when domain providers and other cyber infrastructure providers fail to know their customers.

"Through this case, we hope to demonstrate that if domain owners don’t hold themselves accountable for knowing their customers, they will be held accountable for what is happening on their infrastructure," the blog states. "Our goal is for this case to spur an industry-wide discussion for more public and accountable subdomain registration practices to enable a safer, more secure Internet for all users."

Microsoft’s analysis of the Kelihos botnet showed large portions of Kelihos code were shared with Waledac, which suggested that Kelihos was either from the same parties or that the code was obtained, updated, and reused. "Once we learned of the apparent relationship to Waledac, we immediately began developing a plan to take out Kelihos using similar technical measures," the blog says.

Kelihos is much smaller than Rustock, comprising approximately 41,000 computers worldwide, Microsoft says. Still, the botnet was capable of sending 3.8 billion spam e-mails per day.

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