February 12, 2024 at 08:55PM
Researchers have developed a recovery tool for victims of the Rhysida ransomware, offering a solution to unlock encrypted documents. The ransomware targets various sectors and uses a flawed random number generator, making it possible for the tool to decrypt the data. This tool is distributed by the Korea Internet and Security Agency, providing hope for affected organizations.
Key takeaways from the meeting notes:
1. Smart individuals have developed a recovery tool for victims of the Rhysida ransomware, utilizing an “implementation vulnerability” in the random number generator used by Rhysida to lock up victims’ data, which allowed for the decryption and recovery of the encrypted data.
2. South Korea’s Giyoon Kim, Soojin Kang, Seungjun Baek, Kimoon Kim, and Jongsung Kim have published research explaining their discovery of the implementation vulnerability and the subsequent creation of the Rhysida ransomware recovery tool. The Korea Internet and Security Agency (KISA) is now distributing this tool.
3. The Rhysida ransomware uses intermittent encryption, partially encrypting documents rather than entire files, which is a technique known to be faster than encrypting everything and allows criminals to avoid detection on the network until a considerable number of documents have been affected.
4. The researchers were able to unlock victims’ files despite the prevailing belief that ransomware renders data irretrievable without paying the ransom, using each file’s mtime to determine the order of processing and the time at which each thread executed, ultimately leading to the final decryption key.
5. The US government issued a security advisory in November to help organizations avoid falling victim to the Rhysida ransomware.
Please let me know if you need additional information or if there are specific highlights you would like me to focus on.