CryptoLocker was isolated by the seizure of the Gameover ZeuS botnet as part of Operation Tovar, as formally declared by the U.S. In September 2014, a wave of ransomware Trojans surfaced that initial qualified buyers in Australia, below the names CryptoWall and CryptoLocker (which is, as with CryptoLocker 2., unrelated to the original CryptoLocker). The most current version, CryptoWall 4.