Which versions of matrixkit-js are malicious?

The following npm versions of matrixkit-js are flagged malicious: 1.0.0. Treat any of these as compromised.

How do I remediate matrixkit-js if I installed it?

Remove matrixkit-js 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.

I already installed matrixkit-js — how do I know if it already compromised me?

If matrixkit-js 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.

Is matrixkit-js part of a known attack campaign?

Yes — matrixkit-js is associated with the IN-MAL-2026-019869 campaign. Packages in the same campaign often share infrastructure and payloads, so check whether any related packages are also in your dependency tree.

How do I find matrixkit-js across my projects, lockfiles, and CI pipelines?

Search your lockfiles and build artifacts for matrixkit-js (version 1.0.0).

Malicious package

matrixkit-jsnpm

Advisory published Sep 9, 2026Updated Sep 9, 2026

matrixkit-js is a confirmed malicious npm package (MAL-2026-16095) that executes malicious code on install (malicious version 1.0.0). Do not install it — remove it immediately and rotate any exposed credentials.

Malicious code in matrixkit-js (npm)

MAL-2026-16095

Immediate action

Remove the package, then rotate any secrets the build/runtime could reach.

npm uninstall matrixkit-js

What this malware does

The package advertises itself as a dense-matrix math library but its main entry matrix.js has been modified post-build to require('./src/init') and invoke initMatrix(...) at module load. src/init.js is an obfuscated single-line string-array loader (112-entry rotated array with numeric-index decoder) that uses crypto (aes-256-gcm, scryptSync, createDecipheriv, setAuthTag), fs, path, and zlib to AES-256-GCM-decrypt a base64-encoded on-disk filename, write the decrypted module to a.tmp file, require() it, and invoke its export with a runtime-supplied password. The sibling files src/statMatrix.min.d.js (~1.15MB base64 decoding to ~862KB of high-entropy bytes), src/statMatrix.min.js (~24KB), and src/utilMatrix.min.d.js (~12KB) are single-string base64 blobs decoding to opaque AES-GCM ciphertext — not JavaScript and absent from matrix.js.map, which lists only the clean rollup output. The loader lines are also absent from the source map, confirming they were injected after the legitimate build. On require()ing the package, the encrypted payload is decrypted and executed as opaque author-controlled code.

Malicious versions

1 flagged

1.0.0

Indicators of compromise (SHA-256)

51238ce279c2ff37d32c5edd8a9cb480f1a304720cb67e5acf3ee50e91c773c4

Detection & response playbook

Malicious package

Find it
Search your lockfiles and build artifacts for matrixkit-js (version 1.0.0).
If you installed it — respond
Remove matrixkit-js 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 matrixkit-js 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

No. matrixkit-js on npm has been identified as a malicious package (version 1.0.0 flagged). It should be removed immediately — do not install or keep it in your dependency tree.

Campaign

IN-MAL-2026-019869

References

npmjs.com

Credits

Amazon Inspector · finder

Detect & block this

O3 blocks matrixkit-js-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.

Malware detection Runtime egress monitoring

Explore

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