The downloadable executable "restores original filenames and the full paths of the files recovered," according to the Russian-based anti-virus firm. Kaspersky was the first to identify earlier this month a new and improved variant of the blackmailing Gpcode trojan.
Researchers admit it will be difficult to create a signature for the dangerous malware, which uses virtually uncrackable 1,024-bit encryption. If infected, a user's files -- including MP3s, photos and Word documents -- are encrypted and the original files deleted.
The only way the victim can regain access to the files is if he or she agrees to pay a fee, which is demanded in a pop-up message, Kaspersky researchers have said.
File-recovery software is the best remedy right now, researchers said. The Kaspersky utility leverages the free PhotoRec utility, but adds the ability to restore exact file names and pathways.
Experts first spotted Gpcode about three years ago, when the author used 660-bit encryption to hold victim's files -- including MP3s, photos, documents -- hostage until the user paid up, experts said. That version of the trojan was eventually cracked.
While the new utility is free, Kaspersky is asking victims to consider donating to the PhotoRec creators, who include Christophe Grenier.