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 ever installed, its post-install/runtime payload may have already executed. O3's L7 egress monitoring and runtime eBPF sensors detect the credential exfiltration or command-and-control callback after install and block the malicious outbound channel, so you catch and contain the actual compromise — not just the presence of the package.

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?

Scan your lockfiles (package-lock.json, pnpm-lock.yaml, yarn.lock, requirements.txt, poetry.lock, etc.) and build artifacts for matrixkit-js (version 1.0.0). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging matrixkit-js across your stack and pipelines.

Malicious package

matrixkit-jsnpm

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
Scan your lockfiles (package-lock.json, pnpm-lock.yaml, yarn.lock, requirements.txt, poetry.lock, etc.) and build artifacts for matrixkit-js (version 1.0.0). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging matrixkit-js across your stack and pipelines.
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 ever installed, its post-install/runtime payload may have already executed. O3's L7 egress monitoring and runtime eBPF sensors detect the credential exfiltration or command-and-control callback after install and block the malicious outbound channel, so you catch and contain the actual compromise — not just the presence of the package.
How O3 protects you
O3 blocks matrixkit-js before install through its supply-chain scanner, and if it has already run, detects and severs the exfiltration or C2 callback at runtime through L7 egress monitoring and eBPF.

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

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