tw-fluid-typenpm
Advisory published Updated
tw-fluid-type is a confirmed malicious npm package (MAL-2026-5638) that executes malicious code on install (malicious version 1.0.1). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in tw-fluid-type (npm)
What this malware does
The package advertises itself as a Tailwind CSS fluid-type plugin but ships src/utils/lib.min.js, which is loaded as a side effect when the package's main entry point is required. createClasses.js (reached from src/index.js) does const lib = require('./lib.min.js') and never uses the returned value — the only purpose of the require is to trigger the file's IIFE. lib.min.js caches global.r = require and global.m = module, then runs a ~4KB string through a custom Fisher-Yates-style deterministic shuffle (function YWG, seed 2540575) to decode JavaScript source, resolves the Function constructor via an obfuscated property lookup (YWG['constructor']), and invokes Function(...)(decoded_body) to execute the decoded code with full access to the cached require/module. A declarative CSS-utility plugin has no legitimate need to construct functions from shuffled-string blobs, cache require/module on the global object, or conceal its executable logic with a custom shuffle. Any consumer who imports this package executes the concealed payload at module load.
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
Malicious packageFind it
Search your lockfiles and build artifacts for tw-fluid-type (version 1.0.1).
If you installed it — respond
Remove tw-fluid-type from your project and lockfile, then assume any secrets accessible to the build or runtime were exposed: rotate API keys, tokens, and credentials, and audit for unexpected outbound activity or persistence.
Did it already run?
If tw-fluid-type 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 tw-fluid-type-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.