Which versions of chai-logger are malicious?

The following npm versions of chai-logger are flagged malicious: 3.0.2. Treat any of these as compromised.

How do I remediate chai-logger if I installed it?

chai-logger is built to steal secrets, so assume every credential the build or runtime could read is compromised. Remove it from your project and lockfile, then rotate ALL exposed secrets — npm/registry tokens, cloud keys, CI/CD secrets, SSH keys, and any .env values — from a known-clean machine. Audit logs for unauthorized use of those credentials.

I already installed chai-logger — how do I know if it already compromised me?

If chai-logger 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 chai-logger part of a known attack campaign?

Yes — chai-logger is associated with the IN-MAL-2026-020288 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 chai-logger across my projects, lockfiles, and CI pipelines?

Search your lockfiles and build artifacts for chai-logger (version 3.0.2).

Malicious package

chai-loggernpm

Advisory published Sep 22, 2026Updated Sep 22, 2026

chai-logger is a confirmed malicious npm package (MAL-2026-16380) that steals credentials and exfiltrates sensitive data (malicious version 3.0.2). Do not install it — remove it immediately and rotate any exposed credentials.

Malicious code in chai-logger (npm)

MAL-2026-16380

Immediate action

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

npm uninstall chai-logger

What this malware does

The package presents itself as a Chai logging plugin but its main entry index.js requires ./lib/query.js, a ~4 MB obfuscator.io-encoded module (23,868-entry rotated string array, T/j decoder wrappers, hex-property indirection) that executes at the top level as soon as the package is required. The remaining files under lib/ (proto.js, levels.js, tools.js, etc.) are verbatim copies of pino source, unrelated to the advertised Chai plugin API — a cover story around the obfuscated blob. package.json declares axios ^1.10.0 as a runtime dependency, and the only reference to axios in the shipped code is inside the obfuscated body of lib/query.js, giving the payload an HTTP client whose destination is reconstructed at runtime from the rotated string array. Author metadata points to jsonspack.com, unrelated to Chai or pino. The combination of import-time execution of a heavily obfuscated payload, a mismatched cover story, copied third-party source used as filler, and an HTTP client declared only for use inside the obfuscated code is the canonical npm credential/data-stealer shape.

Malicious versions

1 flagged

3.0.2

Indicators of compromise (SHA-256)

566e54855d730e8555b93da4f8ea81faba72645079a7adcc3a05ea8bf8ad8ee6

Detection & response playbook

Credential / info stealer

Find it
Search your lockfiles and build artifacts for chai-logger (version 3.0.2).
If you installed it — respond
chai-logger is built to steal secrets, so assume every credential the build or runtime could read is compromised. Remove it from your project and lockfile, then rotate ALL exposed secrets — npm/registry tokens, cloud keys, CI/CD secrets, SSH keys, and any .env values — from a known-clean machine. Audit logs for unauthorized use of those credentials.
Did it already run?
If chai-logger 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. chai-logger on npm has been identified as a malicious package (version 3.0.2 flagged). It should be removed immediately — do not install or keep it in your dependency tree.

Campaign

IN-MAL-2026-020288

References

npmjs.com

Credits

Amazon Inspector · finder

Detect & block this

O3 blocks chai-logger-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the credential exfiltration and severs the channel.

Malware detection Runtime egress monitoring

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