The FBI spent much of Tuesday locked in an online tug-of-war with one of the Internet’s most aggressive ransomware groups after taking control of infrastructure the group has used to generate more than $300 million in illicit payments to date.
Early Tuesday morning, the dark-web site belonging to AlphV, a ransomware group that also goes by the name BlackCat, suddenly started displaying a banner that said it had been seized by the FBI as part of a coordinated law enforcement action. Gone was all the content AlphV had posted to the site previously.
Around the same time, the Justice Department said it had disrupted AlphV’s operations by releasing a software tool that would allow roughly 500 AlphV victims to restore their systems and data. In all, Justice Department officials said, AlphV had extorted roughly $300 million from 1,000 victims.
An affidavit unsealed in a Florida federal court, meanwhile, revealed that the disruption involved FBI agents obtaining 946 private keys used to host victim communication sites. The legal document said the keys were obtained with the help of a confidential human source who had “responded to an advertisement posted to a publicly accessible online forum soliciting applicants for Blackcat affiliate positions.”
“In disrupting the BlackCat ransomware group, the Justice Department has once again hacked the hackers,” Deputy Attorney General Lisa O. Monaco said in Tuesday’s announcement. “With a decryption tool provided by the FBI to hundreds of ransomware victims worldwide, businesses and schools were able to reopen, and health care and emergency services were able to come back online. We will continue to prioritize disruptions and place victims at the center of our strategy to dismantle the ecosystem fueling cybercrime.”
Within hours, the FBI seizure notice displayed on the AlphV dark-web site was gone. In its place was a new notice proclaiming: “This website has been unseized.” The new notice, written by AlphV officials, downplayed the significance of the FBI’s action. While not disputing the decryptor tool worked for 400 victims, AlphV officials said that the disruption would prevent data belonging to another 3,000 victims from being decrypted.
“Now because of them, more than 3,000 companies will never receive their keys.”