Microsoft Blocks Waledac Botnet Network

Microsoft has succeeded in its bid to compel .com domain operator VeriSign to deactivate 277 sites that hackers allegedly use to spread the Waledac botnet, which causes infected machines to send spam e-mails. An Alexandria, Virginia, court approved Microsoft’s request for an order to shut down the domains.

Microsoft said that in December alone, the Waledac botnet sent 651 million spam e-mails to Hotmail accounts. With the court order, some 90,000 “zombie” personal computers controlled by the botnet will no longer send spam. The software giant said Waledac is one of the most massive among botnets that operate in the U.S.

Users whose computers are infected by the botnet basically have no idea that their machines are being used to spread spam. Microsoft identified the culprit domains with the help of intelligence organization Shadowserver, Symantec, and the University of Washington.

Microsoft estimates that the Waledac botnet is behind the spread of more than 1.5 billion spam e-mails everyday.