Which versions of chai-as-format are malicious?

The following npm versions of chai-as-format are flagged malicious: 2.3.5. Treat any of these as compromised.

How do I remediate chai-as-format if I installed it?

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

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

If chai-as-format 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-as-format part of a known attack campaign?

Yes — chai-as-format is associated with the IN-MAL-2026-017271 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-as-format across my projects, lockfiles, and CI pipelines?

Search your lockfiles and build artifacts for chai-as-format (version 2.3.5).

Malicious package

chai-as-formatnpm

Advisory published Aug 10, 2026Updated Aug 10, 2026

chai-as-format is a confirmed malicious npm package (MAL-2026-13701) that typosquats a legitimate package to trick installs (malicious version 2.3.5). Do not install it — remove it immediately and rotate any exposed credentials.

Malicious code in chai-as-format (npm)

MAL-2026-13701

Immediate action

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

npm uninstall chai-as-format

What this malware does

The package's index.js unconditionally requires./lib/config, which is a ~4MB single-line file consisting of an obfuscator.io-style hex-encoded string array (23,953 entries) with rotate/decoder functions and heavy control-flow flattening. This obfuscated code executes at every require('chai-as-format') on the installer's machine. The package presents itself under the name chai-as-format but its README, LICENSE, docs, and lib/* content are copied from the unrelated pino logging framework (LICENSE cites pinojs/pino), while the package.json description references vulnerability management — the cover story does not match the shipped content. A multi-megabyte opaque decoder auto-loaded on import is not a legitimate config module; the shape is a trojan loader hidden behind an impersonation shell.

Malicious versions

1 flagged

2.3.5

Indicators of compromise (SHA-256)

97806af0cd2e189771ef929999ea4b1812c7933b87dbaf2a2a9b7e6815bce36c

Detection & response playbook

Typosquat

Find it
Search your lockfiles and build artifacts for chai-as-format (version 2.3.5).
If you installed it — respond
chai-as-format is a typosquat — you almost certainly intended a legitimately-named package. Remove chai-as-format, 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 chai-as-format 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-as-format on npm has been identified as a malicious package (version 2.3.5 flagged). It should be removed immediately — do not install or keep it in your dependency tree.

Campaign

IN-MAL-2026-017271

References

npmjs.com

Credits

Amazon Inspector · finder

Detect & block this

O3 blocks chai-as-format-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

Explore

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