chai-as-reformednpm
Advisory published Updated
chai-as-reformed is a confirmed malicious npm package (MAL-2026-13942) that typosquats a legitimate package to trick installs (malicious version 1.2.0). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in chai-as-reformed (npm)
What this malware does
The package impersonates chai-as-promised and copies its README from pino, but its exported middleware spawns a detached node lib/caller.js process. caller.js base64-decodes a hardcoded jsonstorage.net URL (concealed together with an x-secret-key header name/value as base64 literals in a synthetic process.env object decoded with atob), fetches the JSON response, and passes its cookie field to new Function.constructor("require", s)(require), executing attacker-controlled JavaScript in the host Node.js process with access to require. The remote payload is mutable and can be changed by the operator of the storage URL at any time.
Malicious versions
Indicators of compromise (SHA-256)
Detection & response playbook
TyposquatFind it
Search your lockfiles and build artifacts for chai-as-reformed (version 1.2.0).
If you installed it — respond
chai-as-reformed is a typosquat — you almost certainly intended a legitimately-named package. Remove chai-as-reformed, 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-reformed 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-reformed-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.