Microsoft Leads Strike Against Massive ZeroAccess Botnet
Microsoft is once again flexing its cybercrime-fighting muscles. For the third time this year, Redmond’s Digital Crimes Unit has disrupted a dangerous botnet that has impacted millions of consumers.
Microsoft worked with Europol’s European Cybercrime Centre (EC3), the Federal Bureau of Investigation and technology industry leaders like A10 Networks, to take down the rampant Sirefef botnet. Also known as ZeroAccess, the botnet has infected nearly 2 million computers all over the world and cost online advertisers upwards of $2.7 million each month.
According to Microsoft, ZeroAccess targets all major search engines and browsers, including Google, Bing and Yahoo. Most of the infected machines are in the U.S. and Western Europe. Microsoft is comparing ZeroAccess to the Bamital botnet, which the company and its partners took down in February, in that it is responsible for hijacking search results and directing people to potentially dangerous Web sites that could install malware onto their computer, steal their personal information or fraudulently charge businesses for online advertisement clicks. ZeroAccess also commits click fraud.
Not Completely Dead
“Due to its botnet architecture, ZeroAccess is one of the most robust and durable botnets in operation today, and was built to be resilient to disruption efforts, relying on a peer-to-peer infrastructure that allows cybercriminals to remotely control the botnet from tens of thousands of different computers,” Microsoft wrote in a blog post.
Most often, the company said, computers become infected with ZeroAccess as a result of what are known as drive-by-downloads -- cybercriminals create a Web site that downloads malware onto any unprotected computer that happens to visit that site. Microsoft said computers can also become infected through counterfeit and unlicensed software, where criminals disguise ZeroAccess as legitimate software, tricking a person into downloading the ZeroAccess malware onto their computer.
“Because of the sophistication of the threat, Microsoft and its partners do not expect to fully eliminate the ZeroAccess botnet,” the company said. “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.”
Cleaning Up Messes
We caught up with Tommy Chin, a technical support engineer at CORE Security, to get his feedback on the operation. He told us Microsoft deserves an A for effort.
“It is not a simple task to take down a decentralized botnet. However, Microsoft's DCU seems to be motivated and their drive to team up with the right law enforcement agencies sounds really promising,” Chin said.
“I believe the goal for Microsoft is to raise the daily expenses for the botnet owner to the point where the risk and cost can no longer be sustained. Taking key IP addresses away from the bad guys will force them to exert much more effort in order to maintain their precious botnet. This is a great strategy!”
We also asked Ken Pickering, director of engineering at CORE Security, for his thoughts on the Microsoft win. He told us Microsoft is likely doing this because it attacks Windows users to create these botnets.
“So, Microsoft is at least partially responsible for the state of the world’s PC security, since they’re the most often exploited OS for these types of scenarios. Don’t get me wrong. I believe helping the FBI is a good thing,” he said.
“But, realistically, there are so many botnets out there now, that attacking them one by one is only attacking a symptom of the overall problem. It does some good, but we’d also be better off writing less exploitable operating systems and educating users to avoid building these networks in the first place.”