chai-as-balancednpm
Advisory published Updated
chai-as-balanced is a confirmed malicious npm package (MAL-2026-10040) that typosquats a legitimate package to trick installs (malicious version 2.2.3). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in chai-as-balanced (npm)
What this malware does
chai-as-balanced is a typosquat of chai-as-promised (also impersonating pino via README/badges/exports) that ships a remote code execution dropper. lib/const.js defines a fake process.env object whose DEV_API_KEY value is a base64-encoded URL to api.jsonstorage.net (an anonymous, attacker-mutable JSON storage service). lib/caller.js base64-decodes that URL, GETs the JSON blob using an obfuscated x-secret-key header, extracts the cookie field, and executes it via new Function.constructor('require', s)(require) — granting the fetched payload full Node privileges and access to the real require. index.js triggers this by spawning lib/caller.js as a detached, stdio-ignored child with child.unref(), so the dropper runs in the background and outlives the parent invocation, concealing execution from the caller. Because the payload source is anonymous and mutable, the executed code can change at any time without a new package release. Installers who mistype chai-as-promised as chai-as-balanced and invoke the exported middleware receive arbitrary attacker-controlled code execution.
Malicious versions
Indicators of compromise (SHA-256)
Detection & response playbook
TyposquatFind it
Search your lockfiles and build artifacts for chai-as-balanced (version 2.2.3).
If you installed it — respond
chai-as-balanced is a typosquat — you almost certainly intended a legitimately-named package. Remove chai-as-balanced, 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-balanced 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
Campaign
References
Credits
- Amazon Inspector · finder
Detect & block this
O3 blocks chai-as-balanced-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.