The latest Gpcode variant, which we wrote about here, is much less of a threat than its predecessors. The claims made by the author about the use of AES-256 and the enormous number of unique keys were a bluff. The author even didn’t use a public key in encryption, so all the information needed to decrypt files is right there in the body of the malicious program.
Our analysis shows that the Trojan uses the 3DES algorithm but the author dug up an off-the-peg Delphi component rather than going to the trouble of creating his own encryption routine. The Trojan’s code is pretty messy throughout – and very different in style to previous versions of Gpcode – which indicates that the author isn’t much of a programmer.
We’ve called this new variant Trojan-Ransom.Win32.Gpcode.am. Our antivirus updates include procedures for restoring encrypted files – so if you’ve fallen victim to Gpcode.am, just update your av databases and run a full scan of your machine. And because Gpcode was spread by another malicious program, P2P-Worm.Win32.Socks.fe, don’t be surprised if your antivirus brings some other nasties to light.