MAL-2026-15903 Malicious code in tailwind-container-queries (npm)
Malicious package
Published
MAL-2026-15903 is a malicious package: tailwind-container-queries (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-2026-15903/ (Markdown: https://insights.sbomify.com/MAL-2026-15903/index.md)
- Package
- tailwind-container-queries
- Registry
- npm
What is MAL-2026-15903?
MAL-2026-15903 is a malicious package in tailwind-container-queries, published on 4 Sep 2026.
Official description
On require of the package main, an appended eval(atob(…)) block in dist/index.js queries Ethereum RPC endpoints (eth.blockscout.com/api, 1rpc.io/eth) for the last transaction sent from the hardcoded address 0xa322E5f3D311D3080e6f0121063e9aDC2490Ef1a and decodes the tx.to field into two IPv4 addresses. It fetches XOR-encrypted payloads from http://<resolved-ip>:443/0x/cls and http://<resolved-ip>:443/0x/ls, decrypts them with hardcoded keys, eval's the first payload in-process, and launches the second via spawn('node', ['-e', <decoded>], {detached:true, stdio:'ignore', windowsHide:true}).unref() to leave a persistent detached Node process on the host. After execution the loader rewrites dist/index.js on disk to strip the eval block, removing the payload from the file to hinder later inspection. The package impersonates @tailwindcss/container-queries by copying its README verbatim and pointing the repository field at tailwindlabs/tailwindcss-container-queries. The on-chain C2 pointer lets the operator rotate destination IPs by publishing new Ethereum transactions, so the fetched code is fully attacker-controlled.
What should I do about MAL-2026-15903?
Remove the package from your dependencies and lockfiles, then rotate any secrets on machines where it was installed.