# MAL-2026-6099: Malicious code in stream-read-35cf (npm)


- **Type:** Malicious package
- **Package:** `stream-read-35cf` (npm)
- **Published:** 18 Jun 2026

## What is MAL-2026-6099?

MAL-2026-6099 is a malicious package in stream-read-35cf, published on 18 Jun 2026. 

### Official description

Package declares a postinstall hook ("postinstall": "node run.js") that auto-executes run.js on `npm install`. run.js imports os, fs, http, https, and child_process and collects host identifiers (os.hostname(), os.userInfo(), os.platform(), process.env.USER, process.cwd()), reads files via fs.readFileSync / fs.existsSync, base64-encodes data via Buffer.from(...).toString('base64'), and POSTs the results to remote endpoints over http/https (multiple POST call sites at lines 135, 138, 347, 354). The package name is a short random-suffixed identifier with no documented purpose, and the only effect of installing the package is the reconnaissance + exfiltration payload. This is the canonical install-time stealer shape.

## What should I do about MAL-2026-6099?

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-2026-6099 is a malicious package: stream-read-35cf (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-2026-6099/ (Markdown: https://insights.sbomify.com/MAL-2026-6099/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/MAL-2026-6099

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From sbomify Insights: https://insights.sbomify.com/MAL-2026-6099/
Summaries are generated and may contain mistakes; the official description above is the record.