When Clop was discovered by Jakub Kroustek in February 2019, all indicators showed that it was a new CryptoMix with the .CLOP, or in some circumstances .CIOP, extension tagged onto encrypted files. Since this discovery, the ransomware operators behind Clop have steadily been developing it to move beyond the shadow of merely being a variant of CryptoMix. Soon after Clop’s discovery, it could be argued that the ransomware already could be recognized as a threat in its own right.
Source: Security Boulevard