A newly designated group of North Korean cyber criminals is demanding ransoms of nearly $7 million in exchange for decrypting files on computers they have compromised, cybersecurity researchers at Microsoft Threat Intelligence warned in a report published on Tuesday. 

The group, which Microsoft refers to as “Moonstone Sleet,” reportedly compromised a defense technology firm in December last year before ransoming the same company in April.

The cybercriminals also hacked a supplier of drone technology and compromised a manufacturer of aircraft parts earlier this month, the report revealed.

According to the researchers, Moonstone Sleet appears