After having disrupted the operation of the Waledac and Rustock botnets, Microsoft is going after a smaller one called Kelihos, which they think is an attempt to rebuild Waledac.
Microsoft used the same tactics it did in the previous cases: They went to court and asked for permission to shut down the Internet domains/command-and-control servers for the botnet.
For the first time, though, officials named one defendant in the suit and they notified him of the action.
“In the complaint, Microsoft alleges that Dominique Alexander Piatti, dotFREE Group SRO and John Does 1-22 of owning a domain cz.cc and using cz.cc to register other subdomains such as lewgdooi.cz.cc used to operate and control the Kelihos botnet,” said Richard Boscovich, senior attorney with the Microsoft Digital Crimes Unit. “Our investigation showed that while some of the defendant’s subdomains may be legitimate, many were being used for questionable purposes with links to a variety of disreputable online activities.”
The Kelihos botnet is small, but capable of sending out nearly 4 billion spam emails per day from 41,000 computers worldwide.
“Kelihos infected Internet users’ computers with malicious software which allowed the botnet to surreptitiously control a person’s computer and use it for a variety of illegal activities, including sending out billions of spam messages, harvesting users’ personal information (such as emails and passwords), fraudulent stock scams and, in some instances, websites promoting the sexual exploitation of children,” Boscovich said, adding the cz.cc domain has previously hosted subdomains serving various malware, including the MacDefender rogueware.
After getting a temporary restraining order, Microsoft moved to cut the connections between the C&C centers and the bots. Immediately after the takedown Dominique Alexander Piatti and dotFREE Group SRO got the notice of the lawsuit. Microsoft is still trying to do the same for the other John Doe defendants.
“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,” Boscovich said. “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 will add the Win/32 Kelihos family to its Malicious Software Removal Tool.