# MAL-2026-5763: Malicious code in npm-sandbox-research-g3h4 (npm)


- **Type:** Malicious package
- **Package:** `npm-sandbox-research-g3h4` (npm)
- **Published:** 14 Jun 2026
- **Also known as:** GHSA-p2j4-q5x6-2gc4

## What is MAL-2026-5763?

MAL-2026-5763 is a malicious package in npm-sandbox-research-g3h4, published on 14 Jun 2026. 

### Official description

On install, package.json's postinstall hook executes run.js. The package ships beacon15.js and beacon_linux.js, which import child_process, os, and http and issue outbound HTTP requests carrying host identifiers. beacon_linux.js reads os.hostname() and os.platform() and POSTs them via http.request(); beacon15.js similarly issues GET/http.request() calls referencing host id fields. The combination of a lifecycle hook that runs on every install plus modules that collect host metadata and beacon it outbound matches an install-time host-exfiltration / C2 callback pattern with no legitimate documented purpose.

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-2026-5763?

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-2026-5763 is a malicious package: npm-sandbox-research-g3h4 (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-2026-5763/ (Markdown: https://insights.sbomify.com/MAL-2026-5763/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/MAL-2026-5763

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From sbomify Insights: https://insights.sbomify.com/MAL-2026-5763/
Summaries are generated and may contain mistakes; the official description above is the record.