# MAL-2026-10493: Malicious code in insomnia-plugin-poc-m4gester-run (npm)


- **Type:** Malicious package
- **Package:** `insomnia-plugin-poc-m4gester-run` (npm)
- **Published:** 13 Jul 2026

## What is MAL-2026-10493?

MAL-2026-10493 is a malicious package in insomnia-plugin-poc-m4gester-run, published on 13 Jul 2026. 

### Official description

package.json declares a postinstall lifecycle hook that runs `calc.exe` on the installer's machine during `npm install`. The main entry point exports only an empty `requestHooks` array, providing no actual Insomnia plugin functionality — the package's sole effect is the arbitrary command execution at install time. The name self-identifies as a proof-of-concept and mimics the Insomnia plugin naming convention with a leet-substituted variant, indicating the package exists solely to demonstrate/exploit install-time RCE. While calc.exe itself is benign, the postinstall hook establishes full arbitrary-command-execution capability against any developer installing the package on Windows.

## What should I do about MAL-2026-10493?

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-2026-10493 is a malicious package: insomnia-plugin-poc-m4gester-run (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-2026-10493/ (Markdown: https://insights.sbomify.com/MAL-2026-10493/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/MAL-2026-10493

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From sbomify Insights: https://insights.sbomify.com/MAL-2026-10493/
Summaries are generated and may contain mistakes; the official description above is the record.