# MAL-2026-17576: Malicious code in css-nrmgzn-polyfill (npm)


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

## What is MAL-2026-17576?

MAL-2026-17576 is a malicious package in css-nrmgzn-polyfill, published on 5 Oct 2026. 

### Official description

The package presents itself as a CSS polyfill but on require() of thunderboltRegistry.js runs an IIFE that invokes child_process.execSync for id, whoami, uname, ifconfig, and cat /etc/hosts, and sends the command output together with os.hostname(), node version, platform and pid to a hardcoded Burp Collaborator subdomain at https://unl9pgk6ei4uf80n5tf4iktspjvbuzkn9.oastify.com/. The package also exports modules named after internal Wix thunderbolt registries (thunderboltRegistry, siteAssetsRegistry, editorRegistry, corvidRegistry, documentManagementRegistry) and ships a manifest referencing static.parastorage.com paths for css-nrmgzn-polyfill, consistent with a dependency-confusion lure positioned to resolve in place of a private internal module in a Wix build or CI environment. Loading the package yields host reconnaissance exfiltration to an attacker-controlled OAST domain, with no polyfill functionality actually implemented.

## What should I do about MAL-2026-17576?

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-2026-17576 is a malicious package: css-nrmgzn-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-2026-17576/ (Markdown: https://insights.sbomify.com/MAL-2026-17576/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/MAL-2026-17576

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From sbomify Insights: https://insights.sbomify.com/MAL-2026-17576/
Summaries are generated and may contain mistakes; the official description above is the record.