Cryptolocker ransom

CryptoLocker was not the work of a single individual. It was a ransomware campaign operated by a criminal group (or groups) that linked its activities to the Gameover ZeuS botnet. Law enforcement and investigative reporting have tied the operation to Eastern European cybercriminal activity, but no definitive, publicly confirmed identity of a sole “author” has been disclosed. In short, CryptoLocker is best understood as an organized, multi-person criminal operation rather than a named individual. (en.wikipedia.org)