Law enforcement also announced their disruption of the commoditized NetWalker ransomware.
Criminal hackers can no longer use the notorious Emotet malware to hold the computer networks of schools, hospitals and other critical infrastructure hostage for cash, the Justice Department said, releasing details of its part in a global take down operation.
“The coordinated disruption of Emotet was a great success for the FBI and our international partners,” said FBI Director Christopher Wray, in a press release Thursday. “The FBI utilized sophisticated techniques, our unique legal authorities, and most importantly, our worldwide partnerships to significantly disrupt the malware. The operation is an example of how much we can achieve when we work with our international law enforcement partners to combat the cyber threat. The FBI remains committed, now more than ever, to imposing risk and consequences on cyber criminals to put an end to this type of criminal activity.”
Emotet has been around since at least 2014, according to a Europol, which coordinated the eight-nation law enforcement effort. It first showed up in the banking sector, spread through Word documents, and because bits of its code change with each instantiation, it is difficult to detect. Over the years, this network, or botnet, of infected computers was increasingly used by cyber criminals to gain remote control of all the affected devices and deliver other malware, including ransomware.
The FBI got involved in 2017, when hackers exploited Emotet against a North Carolina school district, disabling its network for weeks, and damaging computers which, along with mitigating the virus, cost $1.4 million, Justice said.
The international law enforcement operation showed the Emotet botnet to be composed of 1.6 million computers around the world between April 1, 2020, and Jan. 17, 2021, with 45,000 of those located in the U.S.
According to a search warrant affidavit the department unsealed, foreign law enforcement, working with the FBI, was able to access an overseas server used to distribute the malicious Emotet updates. Foreign law enforcement created—and with the FBI delivered—a file to Emotet-infected computers that then cut off communications between the victims and the malware administrators. The team identified servers worldwide that were used in the malware distribution and notified the third parties who were unknowingly hosting them, along with those hosting the compromised IP addresses.
“The Emotet malware quickly elevated to one of the top cyber threats in the world,” said Special Agent in Charge Robert R. Wells of the FBI Charlotte Field Office. “The strong relationships with international law enforcement partners were critical to the success of this FBI investigation which began with a small North Carolina school system that did the right thing and quickly contacted their local FBI office for help.”
The Justice Department also highlighted the importance of victims reporting cyber incidents on Wednesday, when it announced another successful international effort that shut down infrastructure used to exploit ransomware known as NetWalker.
In that case, the FBI’s field office in Tampa responded to an attack on the public health sector, designed to take advantage of institutions under strain during the pandemic. Officials worked with authorities in Bulgaria to seize a dark web site that the perpetrators used to communicate their extortions to victims.
Justice charged one individual, a Canadian national named Sebastien Vachon-Desjardins, in association with what officials described as a ransomware-as-a-service operation.
“We are striking back against the growing threat of ransomware by not only bringing criminal charges against the responsible actors, but also disrupting criminal online infrastructure and, wherever possible, recovering ransom payments extorted from victims,” said Acting Assistant Attorney General Nicholas L. McQuaid of the Justice Department’s Criminal Division. “Ransomware victims should know that coming forward to law enforcement as soon as possible after an attack can lead to significant results like those achieved in today’s multi-faceted operation.”