# MAL-2026-6552: Malicious code in insomnia-plugin-poc-m4gester (npm)


- **Type:** Malicious package
- **Package:** `insomnia-plugin-poc-m4gester` (npm)
- **Published:** 28 Jun 2026

## What is MAL-2026-6552?

MAL-2026-6552 is a malicious package in insomnia-plugin-poc-m4gester, published on 28 Jun 2026. 

### Official description

package.json declares a postinstall lifecycle hook that runs a shell command writing a marker file to /tmp on `npm install` (`"postinstall": "echo PWNED_BY_DEEPLINK > /tmp/..."`). The package ships no library code, no plugin implementation, and the description field is literally "test" — there is no advertised functionality to justify the install-time shell execution. The package name `insomnia-plugin-poc-m4gester` further self-identifies as a proof-of-concept exploit targeting the Insomnia REST client plugin namespace. Installing this package results in attacker-chosen shell execution on the installer's machine; the current payload is benign (a marker file write) but the mechanism is arbitrary code execution at install time and could trivially be swapped for a destructive or exfiltrating command in a future version.

## What should I do about MAL-2026-6552?

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-2026-6552 is a malicious package: insomnia-plugin-poc-m4gester (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-2026-6552/ (Markdown: https://insights.sbomify.com/MAL-2026-6552/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/MAL-2026-6552

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From sbomify Insights: https://insights.sbomify.com/MAL-2026-6552/
Summaries are generated and may contain mistakes; the official description above is the record.