commonjs-assertnpm
Advisory published Updated
commonjs-assert is a confirmed malicious npm package (MAL-2026-10676) that executes malicious code on install (malicious versions 1.0.3, 1.0.4). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in commonjs-assert (npm)
What this malware does
The package name resembles Node.js's built-in assert module. On require(), index.js spawns a detached node child process against lib/chai/utils/assertion.js. That file is a single-line obfuscator.io-style bundle (rotated string array, custom-base64 decoder, hex-indexed accessors) whose runtime behavior is to require http/https, perform an HTTP GET against a URL reconstructed from the encoded string array, and pass the response body to new Function(..., body)(require) — remote content fetched at import time and executed with Node's require available. The obfuscation hides the destination URL from static inspection and shields the network-to-eval sink. Any project that requires or imports this package silently triggers arbitrary remote code execution on the installer's host.
Any computer that has this package installed or running should be considered fully compromised. All secrets and keys stored on that computer should be rotated immediately from a different computer. The package should be removed, but as full control of the computer may have been given to an outside entity, there is no guarantee that removing the package will remove all malicious software resulting from installing it.
Malicious versions
Indicators of compromise (SHA-256)
Detection & response playbook
Malicious packageFind it
Search your lockfiles and build artifacts for commonjs-assert (2 malicious versions).
If you installed it — respond
Remove commonjs-assert from your project and lockfile, then assume any secrets accessible to the build or runtime were exposed: rotate API keys, tokens, and credentials, and audit for unexpected outbound activity or persistence.
Did it already run?
If commonjs-assert was installed, its post-install payload may already have run. Removing the package does not undo that — check outbound connections and credential use from the install window onward.
Frequently asked questions
Campaign
References
Credits
- Amazon Inspector · finder
Detect & block this
O3 blocks commonjs-assert-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the malicious outbound activity and severs the channel.