mnchfnvbue1npm
Advisory published Updated
mnchfnvbue1 is a confirmed malicious npm package (MAL-2026-13821) that typosquats a legitimate package to trick installs (malicious version 1.0.0). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in mnchfnvbue1 (npm)
What this malware does
The tarball contains a single file, index.html, declared as the package main. The HTML contains heavily obfuscated JavaScript that mimics a Cloudflare 'Just a moment...' interstitial and, after a 1-second timeout, decodes a string-array to build a URL and calls window.location.replace to navigate a browser to that URL. There are no npm lifecycle scripts (preinstall/install/postinstall/prepare), no bin entry, and main points at a non-JavaScript file, so npm install and require() do not execute this code on an installer's machine. The redirect only fires in a browser rendering the HTML. The package appears to be registry abuse (using npm to host an obfuscated browser redirect asset) rather than a supply-chain attack against installers.
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 mnchfnvbue1 (version 1.0.0).
If you installed it — respond
mnchfnvbue1 is a typosquat — you almost certainly intended a legitimately-named package. Remove mnchfnvbue1, 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 mnchfnvbue1 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 mnchfnvbue1-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.