Security firm asks for help cracking ransomware key
New blackmailing Trojan encrypts files using high-grade 1024-bit RSA key
Computerworld - A security company on Friday asked for help cracking an encryption key central to an extortion scheme that demands money from users whose PCs have been infected by malware.
Kaspersky Lab, a Moscow-based antivirus firm, put out the call for assistance after it discovered a new variant of Gpcode, a Trojan horse that has been used in isolated "ransomware" attacks for the past two years.
In ransomware attacks, hackers plant malware that encrypts files and then displays a message demanding money to unlock the data. In the case of the newest Gpcode, 143 different file types are encrypted, including .bak, .doc, .jpg and .pdf. The encrypted files are marked by the addition of "_CRYPT" in their file names, and the original unencrypted files are deleted. As a camouflaging move, Gpcode also tries to erase itself.
Finally, the ransom note appears on-screen. "Your files are encrypted with RSA-1024 algorithm," it begins. "To recovery [sic] your files you need to buy our decryptor. To buy decrypting tool contact us at: firstname.lastname@example.org."
Last Thursday, a Kaspersky analyst identified as "VitalyK" said that although the company had analyzed samples of Gpcode, it wasn't able to decrypt the files the malware encoded. "We can't currently decrypt files encrypted by Gpcode.ak," said VitalyK in an entry to the company's research blog. "The RSA encryption implemented in the malware uses a very strong, 1024-bit key."
According to Kaspersky's write-up, the key is created by Windows' built-in cryptographic component, Microsoft Enhanced Cryptographic Provider. Kaspersky has the public key in hand — it is included in the Trojan's code — but not the associated private key necessary to unlock the encrypted files.
Two days later, another Kaspersky researcher asked for help. "Along with antivirus companies around the world, we're faced with the task of cracking the RSA 1024-bit key," said Aleks Gostev, a senior virus analyst. "This is a huge cryptographic challenge. We estimate it would take around 15 million modern computers, running for about a year, to crack such a key." Gostev provided the public key in his posting.
"So we're calling on you: cryptographers, governmental and scientific institutions, antivirus companies, independent researchers," said Gostev. "Join with us to stop Gpcode."
One rival researcher, however, took exception to the call to arms. In a message posted to Kaspersky's support forum, Vesselin Bontchev, a Bulgarian researcher who works for Frisk Software, an Icelandic antivirus company, called it a stunt.
"What is proposed here is an unrealistic, useless waste of time that will fail," said Bontchev, who also charged that Kaspersky's estimate of the computing time it would take to break the key was optimistic. "The only use of this project is for generating free publicity for Kaspersky Labs."
- 15 Non-Certified IT Skills Growing in Demand
- How 19 Tech Titans Target Healthcare
- Twitter Suffering From Growing Pains (and Facebook Comparisons)
- Agile Comes to Data Integration
- Slideshow: 7 security mistakes people make with their mobile device
- iOS vs. Android: Which is more secure?
- 11 sure signs you've been hacked
- The 12 PCI DSS 3.0 requirements addressed by Peer 1 Hosting This handy quick reference outlines the 12 PCI DSS 3.0 requirements, who needs to be compliant and how Alert Logic solutions address the...
- Defense Throughout the Vulnerability Life Cycle This whitepaper provides insight into how to leverage threat and log management technologies to protect your IT assets throughout their vulnerability life cycle.
- Mobile Policy Checklist Here's what to consider when putting together a mobile policy designed to support a highly productive workforce.
- Securing BYOD Mobile computing is becoming so ubiquitous that people no longer bat an eye seeing someone working two devices simultaneously. Individuals and organizations are...
- Live Webcast On-demand webinar: "Mobility Mayhem: Balancing BYOD with Enterprise Security" Check out this on-demand webinar to hear Sophos senior security expert John Shier deep dive into how BYOD impacts your enterprise security strategy...
- Live Webcast Endpoint Backup & Restore: Protect Everyone, Everywhere Arek Sokol from the bleeding-edge IT team at Genentech/Roche explains how he leverages cross-platform enterprise endpoint backup in the public cloud as part...
- Streamline Software Asset Management, Compose a software Management Symphony Keeping track of your organization's software is easy with effective software management solutions from CDW. View the videos in our software solutions channel
- Druva inSync: Endpoint Data Protection & Governance CLICK HERE to watch this video about protecting corporate data on laptops and mobile devices, sponsored by Druva. All Security White Papers | Webcasts