Guilty Plea of Ukrainian National for Nefilim Ransomware Attacks
Artem Aleksandrovych Stryzhak, a Ukrainian national, pleaded guilty to conspiracy to commit computer fraud for his role in deploying Nefilim ransomware against high-revenue companies in the United States and other countries. Stryzhak and his co-conspirators generated unique ransomware executables, decryption keys, and ransom notes for each victim, targeting organizations with annual revenues exceeding $100 million and threatening to publish stolen data unless ransoms were paid. He was arrested in Spain in June 2024 and extradited to the United States, where he faces up to 10 years in prison. Authorities are still seeking his alleged co-conspirator, Volodymyr Tymoshchuk, and have announced an $11 million reward for information leading to his arrest or conviction.
The Nefilim ransomware group, for which Stryzhak operated, caused millions of dollars in losses through extortion payments and damage to victim networks. The group primarily targeted companies in the United States, Canada, and Australia, conducting research on potential victims to maximize the impact of their attacks. The U.S. Department of Justice highlighted the international scope of the operation and the significant financial and reputational harm inflicted on victim organizations. Stryzhak’s guilty plea marks a significant development in ongoing efforts to disrupt major ransomware operations and bring perpetrators to justice.
Timeline
May 6, 2026
Stryzhak's sentencing is scheduled for May 2026
Following his guilty plea, Stryzhak faces a maximum sentence of 10 years in prison. Court reporting indicates his sentencing is scheduled for May 6, 2026.
Dec 19, 2025
Artem Stryzhak pleads guilty in U.S. federal court
Stryzhak pleaded guilty to conspiracy to commit computer fraud for his role in Nefilim ransomware attacks targeting high-revenue companies in the U.S. and other countries. He admitted participating in extortion schemes that encrypted systems and threatened to leak stolen data.
Dec 19, 2025
U.S. offers $11 million reward for Volodymyr Tymoshchuk
The U.S. Department of State announced a reward of up to $11 million for information leading to the arrest or conviction of alleged Nefilim administrator Volodymyr Tymoshchuk. He remains at large and is accused of ties to multiple ransomware strains.
Apr 1, 2025
Stryzhak is extradited from Spain to the United States
After his arrest in Spain, Stryzhak was extradited to the U.S. to face federal charges related to conspiracy to commit computer fraud tied to Nefilim ransomware attacks. Reports place the extradition in April 2025.
Jun 1, 2024
Spanish authorities arrest Artem Stryzhak in Barcelona
Stryzhak was arrested in Spain in connection with his role in Nefilim ransomware attacks against organizations in the United States and other countries. Multiple reports place the arrest in June 2024.
Jun 1, 2021
Artem Stryzhak joins the Nefilim ransomware operation
Stryzhak gained access to the Nefilim ransomware code in exchange for a share of ransom proceeds and began participating as an affiliate. He used customized ransomware and ransom notes for individual victims.
Jan 1, 2020
Nefilim ransomware is first observed
Nefilim ransomware was first observed in 2020 and is described as a successor to Nemty. The group used an affiliate model and double-extortion tactics against large enterprises.
Jan 1, 2018
Tymoshchuk-linked ransomware attacks hit organizations in the U.S. and Europe
According to U.S. authorities, Volodymyr Tymoshchuk was involved in ransomware operations including Nefilim, LockerGoga, and MegaCortex that attacked hundreds of organizations in the U.S. and Europe, causing millions of dollars in damage. The activity spanned from 2018 to 2021.
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