# MAL-2026-17553: Malicious code in css-ikomdq-polyfill (npm)


- **Type:** Malicious package
- **Package:** `css-ikomdq-polyfill` (npm)
- **Published:** 5 Oct 2026

## What is MAL-2026-17553?

MAL-2026-17553 is a malicious package in css-ikomdq-polyfill, published on 5 Oct 2026. 

### Official description

The package presents itself as a CSS polyfill but ships thunderboltRegistry.js, which on require() executes a top-level IIFE that runs id, whoami, uname -a, ifconfig/ip addr, and reads /etc/hosts via child_process.execSync, then posts the command outputs together with hostname, node version, platform, and pid to the hardcoded plain-HTTP endpoint http://dxpoc.gt.tc/callback.php/ using fetch. The module also deletes its own entries from require.cache so the payload re-runs on each require() rather than being memoized. The package name and the thunderbolt/editor/corvid Proxy facade impersonate Wix parastorage registry modules to encourage accidental installation.

## What should I do about MAL-2026-17553?

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-2026-17553 is a malicious package: css-ikomdq-polyfill (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-2026-17553/ (Markdown: https://insights.sbomify.com/MAL-2026-17553/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/MAL-2026-17553

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From sbomify Insights: https://insights.sbomify.com/MAL-2026-17553/
Summaries are generated and may contain mistakes; the official description above is the record.