A Moscow court ordered the arrest of three more people allegedly linked to the ransomware group REvil, one day after Russian security agents said they had raided several apartments and seized cash and computer equipment.
The news, announced by the Tverskoi District Court on January 15, brings the number of those arrested in the operation to five.
Russia's Federal Security Service said the January 14 raids were done at the request of U.S. authorities -- something that U.S. officials confirmed later.
It appeared to be a rare demonstration of U.S.-Russian collaboration at a time of soaring tensions between Washington and Moscow.
SEE ALSO: U.S. Welcomes Russia's Arrest Of Alleged Hackers, Including Suspect In Pipeline Ransomware AttackThe Moscow court identified the three new men ordered into custody as Mikhail Golovachuk, Ruslan Khansvyarov, and Dmitry Korotayev.
In its announcement, the security service, known as the FSB, said that its agents had searched 25 addresses and detained 14 people in all. Among the assets the FSB said it had seized were 20 luxury cars.
It wasn't immediately clear when and if the other unnamed individuals detained would be formally arrested.
In November, the United States said it was offering a reward of up to $10 million for information leading to the identification or location of anyone holding a key position in the REvil group.
A senior U.S. administration official told reporters that one of the individuals detained was allegedly behind the May ransomware attack against Colonial Pipeline, which caused a major disruption of gasoline supplies up and down the U.S. East Coast.
At their first summit meeting in June, U.S. President Joe Biden called on Russian President Vladimir Putin to go after cybercriminals operating from inside Russia who target businesses around the world, especially in the United States.
SEE ALSO: U.S. Deports Second Russian Hacker After Long Prison Term EndsRussia-based hackers are believed to be behind a significant proportion of global ransomware attacks.
However, the Kremlin has historically turned a blind eye to their activities as long as they don’t target Russian companies and individuals, experts say.
The two men ordered arrested on January 14 were identified as Andrei Bessonov and Roman Muromsky.