# MAL-2026-5738: Malicious code in postinstall-logger-7x9z (npm)


- **Type:** Malicious package
- **Package:** `postinstall-logger-7x9z` (npm)
- **Published:** 13 Jun 2026
- **Also known as:** GHSA-j5hw-j4vj-f38v

## What is MAL-2026-5738?

MAL-2026-5738 is a malicious package in postinstall-logger-7x9z, published on 13 Jun 2026. 

### Official description

On install, package.json's postinstall hook ("postinstall": "node run.js") triggers execution of bundled beacon scripts (beacon15.js and beacon_linux.js). These scripts pull in child_process, os, and http modules and issue outbound HTTP GET/POST requests carrying host identifiers including os.hostname() and os.platform(). The combination of automatic execution at install time, host-information collection, and outbound HTTP requests to a hardcoded destination is the canonical install-time exfiltration beacon shape. Any developer or CI system running `npm install` for this package will silently leak host data and execute code from the bundled scripts under the installing user's privileges.

Any computer that has this package installed or running should be considered fully compromised. All secrets and keys stored on that computer should be rotated immediately from a different computer. The package should be removed, but as full control of the computer may have been given to an outside entity, there is no guarantee that removing the package will remove all malicious software resulting from installing it.

## What should I do about MAL-2026-5738?

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-2026-5738 is a malicious package: postinstall-logger-7x9z (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-2026-5738/ (Markdown: https://insights.sbomify.com/MAL-2026-5738/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/MAL-2026-5738

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From sbomify Insights: https://insights.sbomify.com/MAL-2026-5738/
Summaries are generated and may contain mistakes; the official description above is the record.