An amount of $5.5 million and 20 luxury cars were seized in an operation carried out at the request of the US, Russian domestic intelligence service says.

An unprecedented attack by the group targeting the US software firm Kaseya affected an estimated 1,500 businesses in July last year.
An unprecedented attack by the group targeting the US software firm Kaseya affected an estimated 1,500 businesses in July last year. (Reuters)

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 hacker group sought by Washington has been dismantled and the United States has been informed of the steps taken by Russia, the domestic intelligence service FSB said on Friday.

"... The organised criminal association has ceased to exist and the information infrastructure used for criminal purposes was neutralised," FSB said on its website.

The equivalent of $5.5 million and 20 luxury cars were seized in the operation, the statement added. 

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 United States.

During a phone call in July, Biden told Putin to "take action" against ransomware groups operating in Russia, warning that otherwise Washington will take "any necessary actions" to defend Americans. 

READ MORE: Kaseya ransomware attack affects up to 1,500 businesses

Reward of up to $10M

The United States said in November that 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.

The United States has been hit by a string of high-profile hacks by ransom-seeking cybercriminals.

The unprecedented attack targeting the US software firm Kaseya affected an estimated 1,500 businesses.

The Kaseya attack, which was reported on July 2, shut down a major Swedish supermarket chain and ricocheted around the world, impacting businesses in at least 17 countries, from pharmacies to gas stations, as well as dozens of New Zealand kindergartens.

Meatpacker JBS SA was hit by the attack that was carried out by the REvilgroup.

Shortly after the attack, the "dark web" page of REvil went offline, sparking speculation about whether the move was the result of a government-led action.

READ MORE: Largest meat producer getting back online after cyberattack

Source: TRTWorld and agencies