Karmen malware is ransomware as a service (RaaS) derived from Hidden Tear, an open source ransomware project, available for purchase by anyone. It encrypts files on the infected machine using the strong AES-256 encryption protocol, making them inaccessible to the user and may trigger a ransom note or instructions demanding that the user pay a large sum of money to obtain the decryption key from the attacker. A notable feature of the malware is that it automatically deletes the decryptor if a sandbox environment or analysis software is detected on the victims computer.”]
Source: https://informationsecuritybuzz.com/articles/karmen-ransomware-variant-introduced-russian-hacker/