Known npm Worm Returns After 111 Days and Security Scanning Still Let It Through

Published September 8, 2026

A known malware worm that hides in npm packages has reappeared after a break. Attackers are slipping malicious code into popular JavaScript tools used by OpenAI and others, bypassing security checks.

Severity
Not scoredNo CVSS score recorded

How it works

  • Attackers hijacked a legitimate npm package maintainer account.
  • They uploaded a malicious version of a widely used JavaScript library.
  • When developers install the package, the worm runs hidden code in their projects.
  • This code can steal secrets, spy on activity, or spread further.
  • The worm avoids detection by mimicking normal package updates.

What to do

Check if you or your team recently installed packages from npm. Look for suspicious activity in your project logs or unexpected code changes. Run npm ls --depth=0 to see installed packages and their versions. If you see any packages updated recently without your approval, investigate further. If you use OpenAI tools or rely on npm for development, assume you are at risk if you installed packages from npm in the last few days.

Uninstall any suspicious packages immediately by running npm uninstall <package-name>. Consult the OpenAI advisory for a documented fix or mitigation. The supplied source does not name an exact fixed version. Enable two-factor authentication on your npm account to prevent account hijacking. Review your project dependencies for any unexpected or unauthorized changes. Consult OpenAI's security advisories for further guidance if you use their tools.

Technical details

A supply-chain attack resurfaced in the npm registry after an 111-day hiatus, exploiting a compromised maintainer account to distribute malicious versions of popular packages. Attackers republished updated versions of packages, including widely used visualization and frontend libraries, with embedded payloads designed to infect downstream projects. The campaign demonstrates how a single compromised account can rapidly escalate into a large-scale software supply-chain compromise, bypassing registry-level security scanning.

References

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