European and U.S. law enforcement agencies teamed up with Intel Security, Kaspersky Lab and the Shadowserver Foundation to disrupt the Beebone botnet, a network of compromised computers that has likely infected hundreds of thousands of systems over six years.
The operation—conducted on April 8 and led by the Dutch National High Tech Crime Unit—seized, registered or suspended the domain names dynamically generated by the botnet as part of its command-and-control network, the organizations said in a statement. The tactic, known as sinkholing, cut the currently compromised systems off from the operators who controlled the botnet.
Beebone, also known as Changeup and W32/Worm-AAEH, was targeted because its creators have been enhancing the malware for nearly six years, Raj Samani, chief technology officer for Intel Security, told eWEEK.
“It’s an incredibly active botnet,” Samani said. “This was quite a sneaky little bugger in its ability to generate domains … it was up to us to understand where the command-and-control infrastructure was going.”
In addition to the Dutch authorities and the FBI, the public agencies that conducted the takedown included Europol’s European Cybercrime Center (EC3), Europe’s Joint Cyber Action Taskforce (J-CAT), and the U. S. National Cyber Investigative Joint Task Force (NCI-JTF) International Cyber Crime Coordination Cell (IC4).
The Beebone botnet has attempted more than 5 million infections in the past six years, with more than 200,000 samples recovered from 23,000 systems between 2013 and 2014. In September 2014, Intel Security detected signs that about 100,000 computers had been infected by Beebone. Because of aggressive efforts to add protections to antivirus software, that number fell to 12,000 infected computers in late March, Samani said.
While no company has a complete picture of the breadth of compromise, the ability to sinkhole all the domains used by Beebone also gave the defenders the ability to see a more complete picture. On Thursday, Intel’s Samani said the latest figures gleaned from the sinkholes showed the number of current infected machines had exceeded 35,000, nearly triple the company’s original estimate.
Companies have conducted coordinated takedowns for more than half a decade. In 2008, hosting provider McColo, which supported the operations of many spammers, lost its links to the wider Internet when its two upstream providers ceased routing traffic.
Spam levels dropped by nearly three-quarters and remained low for months following the takedown. In February 2010, Microsoft embarked on its Microsoft Active Response for Security (MARS) initiative, using court filings and technical investigation to disrupt the Waledac botnet. The company cooperated on nine botnet takedowns, including last year’s dismantling of the Gameover Zeus botnet responsible for spreading Cryptolocker ransomware.
The public sector and private industry need to continue to collaborate to disrupt botnet operations, Intel’s Samani said.
“We are actually working as an industry together to combat this threat,” he said. “For me, it is a wonderful example of … the private sector working with each other as well as working together with law enforcement.”