MAL-2026-12221 Malicious code in tailwind-custom-forms (npm)
- Package
- tailwind-custom-forms
- Registry
- npm
What is MAL-2026-12221?
MAL-2026-12221 is a malicious package in tailwind-custom-forms, published on 5 Aug 2026.
Official description
The package impersonates @tailwindcss/forms: package.json declares the name tailwind-custom-forms while the repository field points at github.com/tailwindlabs/tailwindcss-forms and src/index.js contains a verbatim copy of that legitimate plugin. Appended after module.exports = forms; is eval(atob('<large base64 blob>')), which decodes and executes on any require('tailwind-custom-forms'). The decoded payload reconstructs the module names http, https, zlib, url, and child_process from \u escapes to hide its imports, uses child_process.spawn, and builds outbound HTTP requests with keep-alive agents to hosts resolved at runtime from Ethereum JSON-RPC endpoints (eth.blockscout.com/api, 1rpc.io/eth, eth.drpc.org, ethereum-rpc.publicnode.com, eth-mainnet.public.blastapi.io) keyed off the hardcoded ETH address 0xa322E5f3D311D3080e6f0121063e9aDC2490Ef1a, calling paths /0x/cls and /0x/ls. On-chain records act as a rotating dispatcher so the operator can update C2 hosts without republishing the package. Requiring this module executes attacker-controlled code on the installer's machine.
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.
What should I do about MAL-2026-12221?
Remove the package from your dependencies and lockfiles, then rotate any secrets on machines where it was installed.
Sources
Also known as GHSA-4mgg-vhf5-9r79.