The hackers suspected to be behind a mass ransomware attack that affected hundreds of companies worldwide late on Sunday demanded $70 million to restore the data, according to a posting on a dark web site.
The demand was posted on a site typically used by the REvil cybercrime gang, a Russia-linked group that is counted among the cybercriminal world’s most prolific extortionists.
The gang has an affiliate structure, occasionally making it difficult to determine who speaks on the hackers’ behalf, but Allan Liska of cybersecurity firm Recorded Future said the message “almost certainly” came from REvil’s core leadership.
The group has not responded to an attempt by Reuters to reach it for comment.
REvil’s ransomware attack, which the group executed on Friday, was among the most dramatic in a series of increasingly attention-grabbing hacks.
The gang broke into Kaseya, a Miami-based information technology firm, and used their access to breach some of its clients’ clients, setting off a chain reaction that quickly paralyzed the computers of hundreds of firms worldwide.
Cybersecurity experts swiftly blamed REvil for the attack. Sunday’s statement was the group’s first public acknowledgement that it was behind it.
An executive at Kaseya said the company was aware of the ransom demand but did not immediately return further messages seeking comment.
Liska said he believed the hackers had bitten off more than they could chew.
“For all of their big talk on their blog, I think this got way out of hand and is a lot bigger than they expected,” he said.
The White House said on Sunday it was reaching out to victims of a wide-ranging ransomware outbreak that is centered on a Florida-based information technology company and has had an impact on hundreds of businesses worldwide.
Miami-based Kaseya has said that fewer than 60 of its customers had been “directly affected” by the attack.
But the full impact of the intrusion is still coming into focus, in part because the Kaseya software tool commandeered by the cyber criminals is used by so-called managed service providers, outsourcing shops that other businesses use to handle their back-office IT work, like installing updates.
One cybersecurity executive said his company alone had seen 350 customers attacked.