Which versions of assertcoreutils are malicious?

The following npm versions of assertcoreutils are flagged malicious: 2.3.2, 2.3.3. Treat any of these as compromised.

How do I remediate assertcoreutils if I installed it?

assertcoreutils is a typosquat — you almost certainly intended a legitimately-named package. Remove assertcoreutils, install the correct package, and rotate any secrets exposed during the install since post-install scripts may have already run.

I already installed assertcoreutils — how do I know if it already compromised me?

If assertcoreutils 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 assertcoreutils part of a known attack campaign?

Yes — assertcoreutils is associated with the IN-MAL-2026-010315, IN-MAL-2026-010316, GHSA-22qr-5q9r-7v6x 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 assertcoreutils 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 assertcoreutils (2 malicious versions). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging assertcoreutils across your stack and pipelines.

Malicious package

assertcoreutilsnpm

assertcoreutils is a confirmed malicious npm package (MAL-2026-10491) that typosquats a legitimate package to trick installs (malicious versions 2.3.2, 2.3.3). Do not install it — remove it immediately and rotate any exposed credentials.

Malicious code in assertcoreutils (npm)

MAL-2026-10491

Immediate action

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

npm uninstall assertcoreutils

What this malware does

assertcoreutils impersonates the popular chai assertion library: the README, the chai keyword, the lib/chai/ directory layout, and lib/chai.js are copied verbatim from chai. When a consumer runs require('assertcoreutils'), index.js calls child_process.spawn('node', ['lib/chai/utils/addAssertion.js',...], { detached: true, stdio: 'ignore' }) followed by .unref(), launching a hidden, detached child that survives the parent and produces no console output. lib/chai/utils/addAssertion.js is encoded with obfuscator.io string-array / RC4-base64 obfuscation (hex-named identifiers _0x2ff01b, _0x516b, etc.) that hides a hardcoded HTTPS URL plus query-key; the child performs an HTTPS GET to that URL and passes the response body into new Function('require', body)(require), giving the remote operator arbitrary Node-level code execution on every installer. The combination of typosquat lure, copied legitimate package contents as cover, obfuscated remote URL, detached silent child, and runtime new Function over fetched bytes is a supply-chain dropper.

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

2 flagged

2.3.22.3.3

Indicators of compromise (SHA-256)

1e53b085bfe045b4aeabe9ad77e1066ab0883f27304197377681191c3118b780

2f936d52739c243822b0bbc6aa90d32c07e6c47f5dfd7360316493b1ab00c625

0a5a896a613d498f5908e70719f1b9046f145713db6f66e2c5f4ef101ff46a2b

Detection & response playbook

Typosquat

Find it
Scan your lockfiles (package-lock.json, pnpm-lock.yaml, yarn.lock, requirements.txt, poetry.lock, etc.) and build artifacts for assertcoreutils (2 malicious versions). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging assertcoreutils across your stack and pipelines.
If you installed it — respond
assertcoreutils is a typosquat — you almost certainly intended a legitimately-named package. Remove assertcoreutils, install the correct package, and rotate any secrets exposed during the install since post-install scripts may have already run.
Did it already run?
If assertcoreutils 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 assertcoreutils 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. assertcoreutils on npm has been identified as a malicious package (versions 2.3.2, 2.3.3 flagged). It should be removed immediately — do not install or keep it in your dependency tree.

Campaign

IN-MAL-2026-010315IN-MAL-2026-010316GHSA-22qr-5q9r-7v6x

References

Credits

Amazon Inspector · finder

Detect & block this

O3 blocks assertcoreutils-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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