US Attorney General Merrick Garland and other top officials announced charges against Ukrainian Yaroslav Vasinskyi and Russian Yevgeniy Polyanin, alleging them to be part of the REvil ransomware gang.

Officials said Vasinskyi was recently arrested in Poland and that the US government had recovered $US6.1 million ($A8.2 million) in ill-gotten funds from Polyanin.

“The Justice Department is sparing no resource to identify and bring to justice anyone, anywhere who targets the United States with a ransomware attack,” Garland said.

The US Treasury Department also announced sanctions against the pair as well as what it said was a virtual currency exchange, Chatex, the department said was used by ransomware gangs.

REvil, also known as Sodinokibi, has been linked in recent months to ransomware targeting the world’s largest meat processor, JBS SA, as well as a Fourth of July weekend attack that snarled businesses around the world through a breach of a Florida-based software company called Kaseya.

European law enforcement authorities also announced on Monday that they had arrested two other suspected ransomware operators with links to REvil in Romania.

They are among seven hackers suspected to have links to ransomware attacks that have targeted thousands of victims and have been arrested since last February as part of a global cybercrime crackdown, European agencies said.

None of those arrested hackers was identified by name but Europol said two suspected hackers believed to be linked to the ransomware gang known as REvil were arrested last week for involvement in attacks that yielded about $US580,000 in ransom payments.

Authorities in Kuwait arrested another accused hacker last week and South Korean authorities have arrested three since last February.

A seventh was arrested last month in Europe.

The arrests were part of a law enforcement investigation called GoldDust that involved the United States and 16 other countries.