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Nefilim ransomware suspect extradited from Spain to US

A Ukrainian citizen has been charged and extradited to the United States for allegedly using Nefilim ransomware to attack large companies in the U.S. and elsewhere, federal prosecutors said Thursday.

Artem Stryzhak, 35, was arrested in Spain in 2024 and sent to the U.S. on Tuesday, according to a news release from the U.S. attorney for the Eastern District of New York. He was expected to appear Thursday before a federal judge in Brooklyn.

A highly redacted indictment unsealed Thursday describes the Nefilim ransomware scheme, alleging that Stryzhak and others agreed to give administrators 20 percent of their proceeds in exchange for access to the malware. Prosecutors focused on a spree that started in the summer of 2020 and continued into the fall of 2021.

Nefilim attacks have caused “millions of dollars in losses” overall between ransom payments and damage to computer systems, the news release said. The ransomware operation, also known as Nephilim, was a rebrand of an earlier scheme known as Nemty

Stryzhak’s access to the ransomware began in June 2021, prosecutors said, and he was encouraged to target companies in the U.S., Canada or Australia with more than $200 million in annual revenue. At its peak, Nefilim was known for securing larger payouts in comparison to other operations who were less choosy with targets.

The indictment says Nefilim victims in the U.S. included companies in industries such as aviation, engineering, chemicals, eyewear, insurance, construction, energy and pet care. The ransomware’s users also deployed otherwise legal tools such as the file-transfer software WinSCP and hacking platform Cobalt Strike, the indictment said.

“The perpetrators of Nefilim typically customized the ransomware executable file for each victim, creating a unique decryption key and customized ransom notes,” the news release said. “If the victims paid the ransom demand, the perpetrators sent the decryption key, enabling the victims to decrypt the computer files locked by the ransomware program.”

Stryzhak faces charges of conspiracy to commit fraud and related activity, including extortion, in connection with computers.

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Joe Warminsky

Joe Warminsky

is the news editor for Recorded Future News. He has more than 25 years experience as an editor and writer in the Washington, D.C., area. He previously he helped lead CyberScoop for more than five years. Prior to that, he was a digital editor at WAMU 88.5, the NPR affiliate in Washington, and he spent more than a decade editing coverage of Congress for CQ Roll Call.