"Kaspersky Lab found a new variant of Gpcode, a dangerous encryptor virus has appeared, - Virus.Win32.Gpcode.ak. Gpcode.ak encrypts files with various extensions including, but not limited, to .doc, .txt, .pdf, .xls, .jpg, .png, .cpp, .h and more using an RSA encryption algorithm with a 1024-bit key.

Kaspersky Lab succeeded in thwarting previous variants of Gpcode when Kaspersky virus analysts were able to crack the private key after in-depth cryptographic analysis. Their researchers have to date been able to crack keys up to 660 bits. This was the result of a detailed analysis of the RSA algorithm implementation. It has been estimated that if the encryption algorithm is implemented correctly, it would take 1 PC with a 2.2 Ghz processor around 30 years to crack a 660-bit key.

The author of Gpcode has taken two years to improve the virus: the previous errors have been fixed and the key has been lengthened to 1024 bits instead of 660..."