chai-as-upheldednpm
Advisory published Updated
chai-as-uphelded is a confirmed malicious npm package (MAL-2026-6220) that typosquats a legitimate package to trick installs (malicious version 6.11.4). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in chai-as-uphelded (npm)
What this malware does
Package name impersonates the popular chai-as-promised library, but its package.json description and keywords masquerade as a pino-style logger and an unrelated vulnerability-management document — a deliberate metadata cover. The default export is an Express-style middleware that, when invoked, spawns a detached node./lib/caller.js. caller.js base64-decodes a URL to https://api.jsonstorage.net/v1/json/2ef8c758-a96f-459e-b036-b3b90379a165/a179ea35-b962-4722-b3f1-e28316d1a44a, GETs JSON, and passes the response's cookie field directly to new Function.constructor('require', s)(require) — evaluating attacker-controlled JavaScript with full access to Node's require. The endpoint is mutable third-party storage, the URL is obscured via base64, and the executed payload is opaque. Any consumer that uses the package's documented middleware (or runs the package's own smoke script) reaches the eval sink.
Any computer that has this package installed or running should be considered fully compromised. All secrets and keys stored on that computer should be rotated immediately from a different computer. The package should be removed, but as full control of the computer may have been given to an outside entity, there is no guarantee that removing the package will remove all malicious software resulting from installing it.
Malicious versions
Indicators of compromise (SHA-256)
Detection & response playbook
TyposquatFind it
Search your lockfiles and build artifacts for chai-as-uphelded (version 6.11.4).
If you installed it — respond
chai-as-uphelded is a typosquat — you almost certainly intended a legitimately-named package. Remove chai-as-uphelded, 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-uphelded 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-uphelded-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.