Kaseya, a software company that provides services to more than 40,000 organizations around the world, said on Friday that it was investigating the possibility that it had been the victim of a cyberattack.
The company urged customers that use its systems management platform, called VSA, to immediately shut down their servers to avoid the possibility of being compromised by attackers.
“We are experiencing a potential attack against the VSA that has been limited to a small number of on-premise customers only,” the company posted on its website, referring to organizations that keep their software at their own sites rather than housing it with a cloud provider. “We are in the process of investigating the root cause of the incident with the utmost vigilance.”
Kaseya did not respond to a request for comment.
John Hammond, a researcher at the cybersecurity company Huntress Labs, said that at least eight companies that provide security or technology tools for hundreds of other small businesses might have been “compromised” by the Kaseya attack. He added that REvil, a Russian cybercriminal group that the F.B.I. said was behind the hacking of the world’s largest meat processor, JBS, in May, was most likely to blame.
Some of the affected companies were being asked for $5 million in ransom, Mr. Hammond said. At least 200 companies were at risk, Huntress said.
“Kaseya handles large enterprise all the way to small businesses globally, so ultimately, it has the potential to spread to any size or scale business,” Mr. Hammond said. “This is a colossal and devastating supply-chain attack.”
The United States Cybersecurity and Infrastructure Security Agency also described the incident in a statement on its website as a “supply-chain ransomware attack.” It urged Kaseya’s customers to shut down their servers and said it was investigating.
Hackers have carried out a slate of prominent cyberattacks against U.S. companies in recent months, including JBS and Colonial Pipeline, which moves fuel along the East Coast. Both were ransomware attacks, in which hackers try to shut down systems until a ransom is paid. The video game company Electronic Arts was also recently hacked, but its data was not held for ransom.