Which versions of check-error-util are malicious?

The following npm versions of check-error-util are flagged malicious: 2.1.4. Treat any of these as compromised.

How do I remediate check-error-util if I installed it?

Remove check-error-util 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 network activity or persistence. Use O3 Security's dependency scanner to confirm the package and its artifacts are fully purged across your stack.

Is check-error-util part of a known attack campaign?

Yes — check-error-util is associated with the IN-MAL-2026-005298, IN-MAL-2026-005299 campaign. Packages in the same campaign often share infrastructure and payloads, so check whether any related packages are also in your dependency tree.

Can O3 Security detect check-error-util in my codebase?

Yes. O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, blocking check-error-util and packages like it before any post-install script runs.

Malicious package

check-error-utilnpm

Malicious code in check-error-util (npm) Remove it immediately and rotate any exposed credentials.

MAL-2026-5527

Immediate action

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

npm uninstall check-error-util

What this malware does

Package name and shipped README impersonate the chaijs check-error helper (identical API docs, author attribution, and a spoofed git+ssh://[email protected]/chaijs/check-error.git repository URL), but index.js adds a hidden dropper that runs at module load. A top-level call to resolveConfig() XOR-decodes a 160-byte numeric array (key 87) inside a function cover-named getHashAddress() to produce a hex blob, then uses that blob as an AES-256-CBC key||iv||ciphertext to decrypt an HTTPS URL. The package then calls require('https').get(service,...), JSON-parses the response, and executes the response's cookie field via new Function('require', payload)(require) — handing the live require to attacker-supplied JavaScript with full Node privileges. Any require('check-error-util') or import triggers remote code execution under the installer's account.

Malicious versions

1 flagged

2.1.4

Indicators of compromise (SHA-256)

4354c90de765b6812756121ed6ceb8784ca5a2d6e40f6aa97391e5014c35a038

91cb4f3b95eca0a9d180e159ac28ce3cc697c771229f9447cd1a293ce9cff57d

Frequently asked questions

No. check-error-util on npm has been identified as a malicious package (version 2.1.4 flagged). It should be removed immediately — do not install or keep it in your dependency tree.

Campaign

IN-MAL-2026-005298IN-MAL-2026-005299

References

npmjs.com

Credits

Amazon Inspector · finder

Scan your dependencies

O3 Security blocks malicious packages like this at install time and in CI.

Supply-chain protection