Ransomware strains such as Maze, Ryuk and BlackCat have increasingly been part of FIN7's playbook in recent years, Mandiant says.

European officials do not currently believe that some of the attacks are linked.

The pair of hackers was indicted in November.

The bounty comes some six months after the group breached Colonial Pipeline, vaulting ransomware into the public consciousness.

Attackers are threatening to throw a wrench into major business deals.

Monero appears to be a currency of choice.

DarkSide and REvil were two of the most popular ransomware strains reported.

The ransomware gang BlackMatter was a suspect in a prior incident.

Researchers say online disputes between hackers can be a treasure trove of intelligence.

The Japanse company said it held up data transfers in some business areas as security personnel look into the matter.