Last year attorneys for the software maker quietly sued the hacker group known as Fancy Bear in a federal court outside Washington DC, accusing it of computer intrusion, cybersquatting, and infringing on Microsoft’s trademarks. The action, though, is not about dragging the hackers into court. The lawsuit is a tool for Microsoft to target what it calls “the most vulnerable point” in Fancy Bear’s espionage operations: the command-and-control servers the hackers use to covertly direct malware on victim computers. These servers can be thought of as the spymasters in Russia’s cyber espionage, waiting patiently for contact from their malware agents in the field, then issuing encrypted instructions and accepting stolen documents.
Since August, Microsoft has used the lawsuit to wrest control of 70 different command-and-control points from Fancy Bear. The company’s approach is indirect, but effective. Rather than getting physical custody of the servers, which Fancy Bear rents from data centers around the world, Microsoft has been taking over the Internet domain names that route to them. These are addresses like “livemicrosoft[.]net” or “rsshotmail[.]com” that Fancy Bear registers under aliases for about $10 each. Once under Microsoft’s control, the domains get redirected from Russia’s servers to the company’s, cutting off the hackers from their victims, and giving Microsoft a omniscient view of that servers’ network of automated spies.