Which versions of js-assert-plus are malicious?

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

How do I remediate js-assert-plus if I installed it?

Remove js-assert-plus 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 js-assert-plus — how do I know if it already compromised me?

If js-assert-plus 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 js-assert-plus part of a known attack campaign?

Yes — js-assert-plus is associated with the IN-MAL-2026-017643 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 js-assert-plus 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 js-assert-plus (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 js-assert-plus across your stack and pipelines.

Malicious package

js-assert-plusnpm

js-assert-plus is a confirmed malicious npm package (MAL-2026-13953) 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 js-assert-plus (npm)

MAL-2026-13953

Immediate action

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

npm uninstall js-assert-plus

What this malware does

The npm package js-assert-plus masquerades as an assertion library (homepage http://js-assert-plus.com) and bundles the real chai source so consumers get working functionality while a loader runs on every require/import. index.js hex-decodes the strings 'child_process' and 'spawn' and spawns a detached node subprocess running lib/chai/utils/assertion.js. That sibling module is packed with obfuscator.io string-array obfuscation (rotated array _0x1b90, base64+decodeURIComponent decoder) that reconstructs a URL at runtime, performs an https GET, and passes the response body to new Function('require', body)(require) — executing attacker-controlled JavaScript on the installer's machine with require in scope. Both the require of child_process and the network destination are hidden behind runtime string reconstruction so static inspection cannot see the endpoint.

Malicious versions

1 flagged

1.0.0

Indicators of compromise (SHA-256)

acbf16a8956847ff7ed56158afe65bc0bf76cb36f8cb6af6bc143cae4cb9babe

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 js-assert-plus (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 js-assert-plus across your stack and pipelines.
If you installed it — respond
Remove js-assert-plus 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 js-assert-plus 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 js-assert-plus 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. js-assert-plus 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-2026-017643

References

npmjs.com

Credits

Amazon Inspector · finder

Detect & block this

O3 blocks js-assert-plus-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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