# MAL-2026-12221: Malicious code in tailwind-custom-forms (npm)


- **Type:** Malicious package
- **Package:** `tailwind-custom-forms` (npm)
- **Published:** 5 Aug 2026
- **Also known as:** GHSA-4mgg-vhf5-9r79

## 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.

## Fix prompt for AI coding agents

```text
MAL-2026-12221 is a malicious package: tailwind-custom-forms (npm). Every version was published to cause harm.

Task:
1. Search this repository's dependency manifests and lockfiles for the package, including transitive dependencies.
2. If it is present, remove it, regenerate the lockfile with the project's package manager, and replace whatever it was used for.
3. List any CI runners, developer machines or containers that installed it, so their secrets can be rotated.
4. If the package is not used anywhere, say so and change nothing.

Reference: https://insights.sbomify.com/MAL-2026-12221/ (Markdown: https://insights.sbomify.com/MAL-2026-12221/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/MAL-2026-12221

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From sbomify Insights: https://insights.sbomify.com/MAL-2026-12221/
Summaries are generated and may contain mistakes; the official description above is the record.