CTB Locker (Curve-Tor-Bitcoin Locker), otherwise known as Critroni, is a file-encrypting ransomware infection that was released in July 2014. The media continues to affiliate this infection with CryptoLocker when in fact this appears to have been developed by a different group using new technologies such as elliptical curve cryptography and the malware communicating with the Command and Control server over TOR. This malware also appears to be part of a kit being sold online for $3,000 USD, which includes support in getting it up and running.
Source: https://www.bleepingcomputer.com/virus-removal/ctb-locker-ransomware-information