A longtime former member of Conti, a ransomware group that attacked more than 1,000 organizations globally before it disbanded in 2022, pleaded guilty to participating in some of those attacks in federal court Wednesday, the Justice Department said.

Oleksii Oleksiyovych Lytvynenko, also known as Alexsey Alexseevich Litvinenko, admitted he joined the prolific cybercrime group in September 2021 and held data on 12 victims, including eight based in the United States. The 44-year-old told the court he developed malware that Conti used in some of its attacks, according to officials. 

“The defendant and his conspirators used the Conti ransomware to terrorize people and businesses in the United States and around the world, causing millions of dollars in damage,” A. Tysen Duva, assistant attorney general of the Justice Department’s criminal division, said in a statement.

Lytvynenko and his co-conspirators used the ransomware to attack more than 1,000 victims globally, ensnaring victims in 47 states, Washington, Puerto Rico and about 31 countries, according to the Justice Department. The FBI estimates Conti extorted more than $150 million in ransom payments from victims.

The Ukrainian national pleaded guilty to conspiracy to commit wire fraud and faces up to 20 years in prison upon sentencing, which is scheduled for Sept. 10. 

Lytvynenko was arrested in Ireland in July 2023, extradited to the United States in October 2025, and remains in federal custody in Tennessee where at least three of his victims are based. He left Ukraine in 2022 and obtained temporary protective status in Ireland, residing in Cork at the time of his arrest. 

Prosecutors said Lytvynenko and his co-conspirators extorted about $634,000 in Bitcoin from two victims in Tennessee, including an undisclosed government entity that resulted in the compromise of a sheriff’s department, local emergency medical services and a local police department. According to an indictment that was unsealed last fall, Lytvynenko and his co-conspirators also leaked data they stole from another Tennessee-based victim after it refused to pay a $3 million ransom demand.

Four of Lytvynenko’s alleged co-conspirators — Maksim Galochkin, Maksim Rudenskiy, Mikhail Mikhailovich Tsarev and Andrey Yuryevich Zhuykov — were indicted in 2023 in the same federal court for crimes related to their suspected involvement in Conti attacks from 2020 to 2022. 

Authorities said Lytvynenko engaged in cybercrime after Conti disbanded and its members splintered off into new groups, adding that he “was asleep but within arms’ reach of an open laptop running Cobalt Strike” at the time of his arrest.

At one point, Conti was among the most prolific ransomware groups globally, impacting hundreds of critical infrastructure providers, Costa Rica’s government in 2022, and ultimately leading the State Department to offer a $10 million reward for information related to Conti’s leaders. The group was notoriously resilient, bouncing back with new infrastructure and hitting new targets after a massive leak exposed chats between the group’s members in 2022.

Conti disbanded later that year, but members of the Cyrillic-language group rebranded under three subgroups: Zeon, Black Basta and Quantum, which quickly rebranded to Royal, before rebranding again to BlackSuit in 2024.

“Lytvynenko’s guilty plea is a significant step toward holding cyber criminals accountable for the damage they inflict on victims worldwide,” Brett Leatherman, assistant director of the FBI’s cyber division, said in a statement “Lytvynenko profited from fear and coercion, conspiring to use Conti ransomware to extort victims and steal their data.”