A new ransomware group has been targeting large corporate networks using self-made backdoors and file-encrypting malware for the initial and final stages of the attack. Researchers are tracking the gang using the codename OldGremlin. Their campaigns appear to have started in late March and have not expanded globally, yet. The gang is not picky about victims as long they are prominent businesses in Russia (medical labs, banks, manufacturers, software developers), indicating that it s composed of Russian-speaking members.
Source: https://www.bleepingcomputer.com/news/security/new-ransomware-actor-oldgremlin-uses-custom-malware-to-hit-top-orgs/

