# MAL-2026-5421: Malicious code in @nstrlabs/sdk (npm)


- **Type:** Malicious package
- **Package:** `@nstrlabs/sdk` (npm)
- **Published:** 9 Jun 2026

## What is MAL-2026-5421?

MAL-2026-5421 is a malicious package in @nstrlabs/sdk, published on 9 Jun 2026. 

### Official description

On `npm install`, package.json runs `preinstall: node index.js || true`, unconditionally executing index.js. The script collects host identity fields (os.hostname(), os.userInfo().username, __dirname, process.cwd(), and the package id), hex-encodes them as DNS labels, and resolves them as a subdomain of an interactsh OOB callback host (`*.d8jbmnsqcfu78dfs8vdg34ohqhirb4pbg.oast.live`), then also POSTs the same JSON payload to a bare IP HTTP endpoint at `http://172.201.213.59:9090/c`. Two independent exfiltration channels (DNS + HTTP) fire on every install, with `|| true` swallowing errors so the exfil is silent. The package is a typosquat / dependency-confusion lure: version `99.0.1` is an unusually high pseudo-version, scope `@nstrlabs` and metadata (`description: security research`, author `jeroengui`) are placeholder-shaped, and the package has no other functionality — its sole effect on install is the recon beacon.

## What should I do about MAL-2026-5421?

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-2026-5421 is a malicious package: @nstrlabs/sdk (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-2026-5421/ (Markdown: https://insights.sbomify.com/MAL-2026-5421/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/MAL-2026-5421

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From sbomify Insights: https://insights.sbomify.com/MAL-2026-5421/
Summaries are generated and may contain mistakes; the official description above is the record.