[Shai-Hulud](https://attack.mitre.org/software/S9008) is a supply chain worm, first reported in September 2025, that spreads through code repositories, including GitHub and NPM packages. It exploits CI/CD pipeline dependencies to propagate to victims and poisons the supply chain by publishing malicious packages. Once inside a victim environment, [Shai-Hulud](https://attack.mitre.org/software/S9008) steals credentials and access tokens from compromised repository accounts and exfiltrates them to attacker-controlled servers via encoded GitHub Actions workflows.(Citation: Palo Alto Unit 42 Shai-Hulud November 2025)(Citation: Microsoft Shai-Hulud December 2025)(Citation: Socket Shai-Hulud November 2025)(Citation: Socket Shai-Hulud Trufflehog September 2025)(Citation: Aikido Shai-Hulud September 2025)(Citation: Netskope Shai-Hulud November 2025)(Citation: Wiz Shai-Hulud September 2025)