https://www.halcyon.ai/blog/abusing-aws-native-services-ransomware-encrypting-s3-buckets-with-sse-c
A new ransomware campaign leverages Amazon Web Services’ (AWS) Server-Side Encryption with Customer Provided Keys (SSE-C) to encrypt victims’ data stored in S3 buckets. This tactic, discovered by cybersecurity firm Halcyon, sees threat actors, such as the group dubbed “Codefinger,” infiltrate AWS accounts and utilize the SSE-C feature with their own encryption keys.
The campaign hinges on the fact that AWS does not store these customer-provided keys. This makes data recovery impossible for victims even if they report the incident to Amazon. After encrypting the data, attackers set a seven-day file deletion policy and leave ransom notes demanding Bitcoin payments in exchange for the decryption key.
Halcyon advises AWS customers to implement strict security protocols, including disabling unused keys, regularly rotating active keys, and minimizing account permissions. They also recommend setting policies that restrict the use of SSE-C on S3 buckets where possible.
This incident highlights the critical need for robust security measures within cloud environments, emphasizing the importance of secure key management and vigilant monitoring for unauthorized activity.