✅ Report Title: Megalodon: Software Supply Chain Attack Campaign Report

✅ Executive Summary:

- On May 21, 2026, Megalodon, a large-scale supply chain attack campaign targeting GitHub, was identified and subjected to detailed analysis.

- According to SafeDep and OX Security, the campaign committed malicious files to over 5,500 GitHub repositories in about 6 hours.

📌 Distribution Process and Potential Impact

- The threat actor compromised legitimate GitHub repositories and tampered with Action workflow files.

- As a result, when users utilizing the Github Action workflow clicked Run Workflow or executed it through the API, a tampered payload was executed.

- If the payload is executed, it performs extensive credential compromise within the system where the code is executed, including credentials for cloud services, and these are sent to a C2 server controlled by the threat actor.

- Ultimately, the threat actor can use the compromised credentials to carry out additional attacks, such as accessing and tampering with additional systems.

📌 Detailed Analysis

- The malicious workflow, altered by the threat actor, executes a Base64-encoded payload.

- The decrypted payload creates a temporary directory upon execution and collects extensive sensitive information within the compromised system, including environment variables, authentication tokens, AWS-related credentials, and secret files.

- The collected sensitive information is sent to the C2 server via a POST request.

- After the above credential and information compromise has been performed, the temporary directory used to store the command execution results is deleted through the command 'trap "rm -rf '$TMP_DIR'" EXIT'.

- This is considered a process to minimize traces that may be identified during subsequent forensic procedures.

✅ Recommended Threat Detection and Mitigation Actions:

- This malware collects extensive credentials, such as source code repositories and CI/CD environments, upon execution, potentially expanding the attack scope and enabling further compromise of internal systems upon infection.

- Therefore, measures such as integrity verification of repositories and CI/CD environments, periodic replacement of tokens used for extended periods, and minimizing the storage of credentials within the system are necessary.

- If signs of infection by the malware are identified, all potentially exposed credentials must be immediately revoked and reissued.

🧑‍💻 Author: S2W TALON

👉 Contact us: https://s2w.inc/en/contact

*The full report is available upon request or with a subscription to the S2W platform.