CryptoLocker

The 2013 trojan that proved file-encrypting extortion pays, igniting the modern ransomware economy.

Core Principles & Analysis

• It encrypted victims’ files with strong RSA and sold the private key back for Bitcoin.
• It spread largely through the Gameover ZeuS botnet and malicious attachments.
• Operation Tovar in 2014 seized its infrastructure and recovered keys for free decryption.