Russia has conducted a special operation against ransomware crime group REvil at the request of the United States and has detained and charged the group's members, the FSB domestic intelligence service says.
The hacker group sought by the United States has been dismantled and US officials have been informed of the steps taken by Russia, the FSB said on its website.
"The organised criminal association has ceased to exist and the information infrastructure used for criminal purposes was neutralised," it said.
The US embassy in Moscow said it could not immediately comment.
A source familiar with the case told Interfax that the group's members with Russian citizenship would not be handed over to the US.
The US government said in November it was offering a reward of up to $US10 million ($A14 million) for information leading to the identification or location of anyone holding a key position in the REvil group.
The US has been hit by a string of high-profile hacks by ransom-seeking cybercriminals.
Meatpacker JBS SA was hit by a ransomware attack that was carried out by the REvil group, a source with direct knowledge of the matter told Reuters in June.
Russia's announcement comes during a standoff between the United States and Russia. Moscow is demanding Western guarantees including that NATO will not expand further. It has also built up its troops near Ukraine.
