The second principle is that Mr. Putin ordered the group’s websites taken down. In that case, that will be a gesture towards heeding Mr. Biden’s warning, which he had additionally conveyed, in additional normal phrases, when the 2 leaders met on June 16 in Geneva. And it could come only a day or two earlier than a U.S.-Russia working group on the problem, arrange in the course of the Geneva assembly, is meant to carry a digital assembly.

A 3rd principle is that REvil determined that the warmth was too intense, and took the websites down itself to keep away from turning into caught within the crossfire between the American and Russian presidents. That’s what one other Russian-based group, DarkSide, did after the ransomware assault on Colonial Pipeline, the U.S. firm that in Might needed to shut down the pipeline that gives gasoline and jet gasoline to a lot of the East Coast after its pc community was breached.

However many specialists assume that DarkSide’s going-out-of-business transfer was nothing however digital theater, and that all the group’s key ransomware expertise will reassemble beneath a distinct identify. In that case, the identical might occur with REvil, which Recorded Future, a Massachusetts cybersecurity agency, estimates has been chargeable for roughly 1 / 4 of all the delicate ransomware assaults on Western targets. .

Allan Liska, a senior intelligence analyst at Recorded Future, stated that if REvil has disappeared, he doubted it was voluntary. “If something, these guys are braggadocios,” Mr. Liska stated. “And we didn’t see any notes, any bragging. It positive looks like they deserted the whole lot beneath strain.”

There have been options that the strain might have come from Russia. The commander of United States Cyber Command and director of the Nationwide Safety Company, Gen. Paul M. Nakasone, was not anticipated to get the complete choices for U.S. motion in opposition to ransomware actors till later this week, a number of officers stated. And there was no proof that REvil’s websites had been “seized” by a court docket order, which the Justice Division steadily posts.

Cyber Command declined to remark.

Whereas shutting REvil for now would give Mr. Putin and Mr. Biden an opportunity to point out they had been confronting the issue, it might additionally give the ransomware actors a possibility to stroll away with their winnings. The large losers could be the businesses and cities that don’t get their encryption keys, and are locked out of their information, maybe perpetually. (Typically when ransomware teams disband, they publish their decryption keys. That didn’t occur on Tuesday.)

Mr. Biden is anticipated to roll out a ransomware technique in coming weeks, making the case that Colonial Pipeline and different latest assaults present how crippling vital infrastructure constitutes a serious nationwide safety menace.