ESET and Sophos have discovered the first self-reproducing polymorphic Ransomware dubbed Virlock. The new strain of ransomware, dubbed VirRansom or VirLock, discovered by the experts is able to encrypt the file on victims host and creates unique instances of itself due to its polymorphic feature. VirLock allows decryption of the files, but it will not stop locking the screen as an extortion mechanism to force the victim to pay. At the moment, the experts have detected at least six variants of the malware circulating in the wild.”]
Source: http://securityaffairs.co/wordpress/31442/malware/virlock-polymorphic-ransomware.html