Shai Hulud 3.0 exposes how trusted open source npm dependencies are being weaponised to breach developer pipelines, as security experts warn of escalating supply chain risks across software ecosystems.
A third variant of the Shai Hulud malware, dubbed Shai Hulud 3.0, has been discovered, raising renewed concerns over the security of the open source software supply chain, particularly within the JavaScript ecosystem.
The malware targets open-source dependencies, spreading through trojanised npm (Node Package Manager) packages rather than traditional endpoint infection. By embedding malicious code into trusted open-source components, attackers are able to bypass perimeter defences and gain access to high-value systems downstream.
Shai Hulud 3.0 is a self-propagating worm aimed at JavaScript developers. While retaining its ability to spread laterally across developer environments and compromise continuous integration pipelines, the latest variant introduces greater technical sophistication. Enhancements include improved error handling, a more modular codebase, stronger obfuscation techniques, broader compatibility across JavaScript runtimes, and explicit support for Windows environments, improving stealth, resilience and evasion.
The new variant has so far been distributed through a smaller number of npm packages than earlier versions, suggesting a controlled rollout as threat actors test updated malware before wider deployment.
Shai Hulud was first observed in September, with a second variant detected just before Christmas by Expel Inc. The 3.0 version was first identified by Aikido Security NV.
Patrick Munch, Chief Security Officer at Mondoo Inc., warned that 3.0 is an “indiscriminate ‘fire and forget’ weapon with no way of calling off the attack,” adding that “its rapid evolution is a stark reminder that the software supply chain remains a primary target for threat actors.”
“Attacking the core of the software supply chain gives attackers a broad scope to harvest credentials and cause chaos,” Munch said. “We expect to see a rise in similar high-impact attacks across multiple software development ecosystems.”
