After discovering a new and improved virus that encrypts important files on infected machines, researchers from Kaspersky are calling on fellow security professionals to lend a hand in cracking the massive key needed to liberate the ensnared data.

The call to arms posted Friday comes two days after the antivirus provider detected a new variant of a malicious file-encryptor dubbed Gpcode. It surreptitiously encrypts a variety of files, including photos and those used by MS Word and Excel and Adobe Reader. Victims can only recover the missing booty by paying a ransom to the miscreants.

Cryptographers won't have as easy a task this time around. Gpcode uses a 1024-bit key and the algorithm seems to be sound, so brute-forcing the scheme will require about 15 million modern computers, and even then, it could take about a year.

"Of course, we don't have that type of computing power at our disposal," Kaspersky says in its appeal. "This is a case where we need to work together and apply all our collective knowledge and resources to the problem."

They've included two public keys - one used to encrypt files on XP and Vista machines and the other for all other versions of Windows. And they've also provided the exponent for the keys. They're especially interested in someone stepping forward with a custom-built application that can tackle the tough job of factoring the key. A forum for the project is here. ®

Related stories

• Ransomware author tracked down, but not nicked (1 October 2008)
• Updated Ransomware Trojan code break 'impractical' (13 June 2008)
• Chinese mobile users targeted by Trojan (5 March 2008)
• Ransomware Trojan locks up infected PCs (3 January 2008)
• The return of the ransom-ware Trojan (19 July 2007)
• Ransomware getting harder to break (24 July 2006)
• Ransomware Trojan cracked (6 June 2006)