Malware
Clop
Clop is a ransomware which uses the .clop extension after having encrypted the victim's files.
Clop is a Windows malware family operated by TA505.
Background
Clop is a ransomware that appends the .clop extension to the files it encrypts. A distinctive trait is the string "Dont Worry C|0P", which appears in its ransom notes. Derived from the CryptoMix ransomware, Clop additionally tries to disable Windows Defender and uninstall Microsoft Security Essentials to evade detection in user space.
Source: Malpedia (Fraunhofer FKIE).