# MAL-2026-6710: Malicious code in vitest-agent (npm)


- **Type:** Malicious package
- **Package:** `vitest-agent` (npm)
- **Published:** 1 Jul 2026
- **Also known as:** GHSA-w2r4-4x6j-3h5x

## What is MAL-2026-6710?

MAL-2026-6710 is a malicious package in vitest-agent, published on 1 Jul 2026. 

### Official description

The package's postinstall script (`node lib/utils/index.js`) spawns a detached, stdio-suppressed Node child process that runs `lib/utils/smtp-connection/index.js`. That file fetches JavaScript from `https://jsonkeeper.com/b/WDH3V` via axios and executes the response with `new Function("require", r.data.cookie)(require)`, running unpinned, mutable, non-publisher code on the installer's machine at `npm install` time. The package is named `vitest-agent` but its `main` and shipped source are a verbatim copy of nodemailer (author field `Andris Reinman`, description is an unrelated React copyright string), a name/identity mismatch consistent with a lure targeting vitest ecosystem users. Concealment signals reinforce the dropper: a ~256 KB `LICENSE` file sits adjacent to a 185-byte dropper `index.js` under `lib/utils/smtp-connection/`, and path names mirror legitimate nodemailer layout as cover. Because the harmful code path fires automatically from the postinstall lifecycle hook, installers are compromised without any explicit user action beyond installing the package.

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-2026-6710?

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-2026-6710 is a malicious package: vitest-agent (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-2026-6710/ (Markdown: https://insights.sbomify.com/MAL-2026-6710/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/MAL-2026-6710

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From sbomify Insights: https://insights.sbomify.com/MAL-2026-6710/
Summaries are generated and may contain mistakes; the official description above is the record.