North Korean state-backed hackers appear to be cooperating with Eastern European cybercriminals, a report said on Wednesday, a finding that suggests digital gangsters and state-backed spies are finding common ground online.

Mountain View, California-based SentinelOne says that the Lazarus Group – which American prosecutors accuse of organizing the leak of emails from Sony Pictures and stealing millions of dollars from the Central Bank of Bangladesh – is getting access to some of its victims through a cybercrime gang dubbed “TrickBot.”

“For me it’s the biggest crimeware story since I don’t-know-when,” said Vitali Kremez of SentinelOne. “The Lazarus group has a relationship with the most sophisticated, most resourceful Russian botnet operation on the landscape.”

Hints that Lazarus and TrickBot operators are cooperating had surfaced previously. In April, a BAE researcher said she and others were weighing the theory that the cybercriminals were selling access to compromised organizations to Lazarus, a bit like a fence selling stolen doorkeys to a burglar.

In July, the cybersecurity arm of Japanese telecommunications company NTT speculated that North Korea might be collaborating with Lazarus and TrickBot’s operators.

Kremez said he found evidence. TrickBot communicated with a Lazarus-controlled server just a couple of hours before that same server was used to help break into the Chilean interbank network earlier this year, he said. American officials have also blamed the multimillion dollar heist on North Korea.

“That’s the strongest possible evidence linking to a celebrated case of Lazarus intrusion,” said Kremez.

Kremez said that the TrickBot operators were likely renting out its services to the North Koreans, or perhaps working on a commission basis.

The judgment was seconded by Assaf Dahan of Boston-based Cybereason, which is publishing its own, separate report on Trickbot’s operations Wednesday. He reviewed SentilOne’s research and said its conclusions were credible, adding that he was certain that the cybercriminals knew that they were dealing with the North Korean government.

“Whether they care or not is a different thing,” he said.