Researchers have demonstrated a method for cracking the Akira ransomware's encryption using sixteen RTX 4090 GPUs. By exploiting a vulnerability in Akira's implementation of the ChaCha20 encryption algorithm, they were able to brute-force the 256-bit encryption key in approximately ten hours. This breakthrough signifies a potential weakness in the ransomware and offers a possible recovery route for victims, though the required hardware is expensive and not readily accessible to most. The attack relies on Akira's flawed use of a 16-byte (128-bit) nonce, effectively reducing the key space and making it susceptible to this brute-force approach.
The blog post details a successful effort to decrypt files encrypted by the Akira ransomware, specifically the Linux/ESXi variant from 2024. The author achieved this by leveraging the power of multiple GPUs to significantly accelerate the brute-force cracking of the encryption key. The post outlines the process, which involved analyzing the ransomware's encryption scheme, identifying a weakness in its key generation (a 15-character password), and then using Hashcat with a custom mask attack on the GPUs to recover the decryption key. This allowed for the successful decryption of the encrypted files, offering a potential solution for victims of this particular Akira variant without paying the ransom.
Several Hacker News commenters expressed skepticism about the practicality of the decryption method described in the linked article. Some doubted the claimed 30-minute decryption time with eight GPUs, suggesting it would likely take significantly longer, especially given the variance in GPU performance. Others questioned the cost-effectiveness of renting such GPU power, pointing out that it might exceed the ransom demand, particularly for individuals. The overall sentiment leaned towards prevention being a better strategy than relying on this computationally intensive decryption method. A few users also highlighted the importance of regular backups and offline storage as a primary defense against ransomware.
Summary of Comments ( 11 )
https://news.ycombinator.com/item?id=43387188
Hacker News commenters discuss the practicality and implications of using RTX 4090 GPUs to crack Akira ransomware. Some express skepticism about the real-world applicability, pointing out that the specific vulnerability exploited in the article is likely already patched and that criminals will adapt. Others highlight the increasing importance of strong, long passwords given the demonstrated power of brute-force attacks with readily available hardware. The cost-benefit analysis of such attacks is debated, with some suggesting the expense of the hardware may be prohibitive for many victims, while others counter that high-value targets could justify the cost. A few commenters also note the ethical considerations of making such cracking tools publicly available. Finally, some discuss the broader implications for password security and the need for stronger encryption methods in the future.
The Hacker News post titled "Akira ransomware can be cracked with sixteen RTX 4090 GPUs in around ten hours" has generated several comments discussing the implications of using powerful GPUs like the RTX 4090 for cracking encryption.
Some users express skepticism about the practicality of this approach. One commenter questions the feasibility for average users, pointing out the significant cost of acquiring sixteen RTX 4090 GPUs. They suggest that while technically possible, the financial barrier makes it unlikely for most victims of ransomware. Another user echoes this sentiment, highlighting that the cost would likely exceed the ransom demand in many cases. They also raise the point that this method might only work for a specific vulnerability in Akira and wouldn't be a universal solution for all ransomware.
Others discuss the broader implications of readily available GPU power. One comment points out the increasing accessibility of powerful hardware and its potential to empower both security researchers and malicious actors. They argue that this development underscores the ongoing "arms race" in cybersecurity, where advancements in technology benefit both sides. Another user suggests that this highlights the importance of robust encryption practices, as the increasing power of GPUs could eventually render weaker encryption methods vulnerable.
A few comments delve into the technical aspects. One user questions the specific algorithm used by Akira and speculates on its susceptibility to brute-force attacks. Another user mentions the importance of key length and how it affects the time required for cracking, emphasizing that longer keys would significantly increase the difficulty even with powerful GPUs.
One commenter points out the article's potentially misleading title. They clarify that the GPUs weren't cracking the encryption itself, but rather brute-forcing a password which was then used to decrypt the files. This distinction is important, as it implies a weakness in the implementation rather than the underlying encryption algorithm.
Finally, a few users offer practical advice. One suggests using strong, unique passwords to protect against this type of attack, emphasizing the importance of basic security hygiene. Another user proposes that the best defense against ransomware remains regular backups, allowing victims to restore their data without paying the ransom.
Overall, the comments reflect a mix of concerns about the practical implications of using GPUs for cracking ransomware, discussions about the broader cybersecurity landscape, and technical insights into the vulnerabilities highlighted by this specific case.