Description

A new and highly aggressive supply-chain attack, dubbed Sha1-Hulud, is targeting the npm ecosystem in a campaign reminiscent of the earlier Shai-Hulud incident. Multiple security vendors report that hundreds of npm packages were trojanized and uploaded between November 21 and 23, 2025, affecting well-known projects from organizations such as Zapier, ENS Domains, PostHog, and Postman. The attackers introduced a malicious preinstall script (“setup_bun.js”) that stealthily installs or locates the Bun runtime and executes a secondary payload (“bun_environment.js”). Once triggered, the malware registers the victim machine as a “SHA1HULUD” self-hosted GitHub runner and deploys a rogue workflow enabling remote command execution. It then exfiltrates GitHub Actions secrets by packaging them as “actionsSecrets.json,” uploading them to attacker-controlled repositories, and removing evidence to avoid detection. The payload also downloads and runs TruffleHog to capture sensitive credentials, including npm tokens and cloud provider keys. Due to automated replication, the campaign has impacted over 27,000 repositories across 350 users, with thousands of new infections appearing rapidly. The malware supports Linux, macOS, and Windows, and even performs cross-victim exfiltration by storing one victim’s secrets in another victim’s public repository. If unable to authenticate or obtain credentials, the threat activates a destructive fallback designed to wipe the user’s entire home directory—an escalation from simple theft to deliberate sabotage. It can also gain root access on Linux hosts by abusing Docker to deploy a malicious sudoers file. Organizations are urged to immediately remove compromised packages, rotate exposed credentials, and audit GitHub workflows for persistence artifacts related to the attack.