Ukrainian Stryzhak pleads guilty to mass ransomware attacks

Eastern District of New York Federal Court in Brooklyn. Brooklyn Eagle photo by Rob Abruzzese

DOWNTOWN — IN FEDERAL COURT IN BROOKLYN on Friday, Ukrainian national Artem Stryzhak pleaded guilty to conspiracy to commit cybercrime fraud and related activities including extortion, for his role in a series of international ransomware attacks. Stryzhak was arrested in Spain in June 2024 and extradited to the United States on April 30, 2025.

“The defendant used Nefilim ransomware to target high-revenue companies in the United States, steal data and extort victims,” U.S. Attorney for the Eastern District of New York Joseph Nocella said in a statement.

In June 2021, the administrators of the illicit Nefilim ransomware operation gave Stryzhak access to their code in exchange for 20% of his proceeds. Stryzhak used the ransomware to encrypt computer networks in countries around the world, including in the Eastern District of New York, causing millions of dollars in losses and damage to the victims’ computer systems, Nocella said. Nefilim ransom notes typically threatened the victims that unless they came to an agreement with the criminals, the stolen data would be published on publicly accessible “Corporate Leaks” websites.

When sentenced, Stryzhak faces up to 10 years’ imprisonment. His co-conspirator, Volodymyr Tymoshchuk, remains at large and is the subject of a $11 million reward offered by the U.S. Department of State. Anyone with information should contact the FBI via phone at +1-917-242-1407 or by email at [email protected].

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