# MAL-2026-17522: Malicious code in studiocode_eligibility (npm)


- **Type:** Malicious package
- **Package:** `studiocode_eligibility` (npm)
- **Published:** 4 Oct 2026

## What is MAL-2026-17522?

MAL-2026-17522 is a malicious package in studiocode_eligibility, published on 4 Oct 2026. 

### Official description

package.json declares a postinstall hook `wscript.exe 4444.vbs` that automatically executes a 765KB VBScript shipped in the tarball on Windows installers. The VBS contains multi-layer obfuscation (XOR-decoded AES S-boxes, SHA-256 constants, a ChaCha20 stream layer, and a large Base64 'ArtifactBundleHX' blob) that decrypts a PowerShell loader, writes it to %TEMP%\pf#####.dat, and invokes it via powershell.exe using process-hollowing-style techniques. The library source (src/index.js) is a small Zod-based email-domain eligibility checker that is unrelated to the VBS payload and serves as cover. The README explicitly claims 'Checks run locally, without network requests' and 'There are no installation scripts', directly contradicting the declared postinstall hook and shipped dropper. Running `npm install studiocode_eligibility` on Windows grants the package author arbitrary code execution on the installer's machine.

## What should I do about MAL-2026-17522?

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-2026-17522 is a malicious package: studiocode_eligibility (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-2026-17522/ (Markdown: https://insights.sbomify.com/MAL-2026-17522/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/MAL-2026-17522

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From sbomify Insights: https://insights.sbomify.com/MAL-2026-17522/
Summaries are generated and may contain mistakes; the official description above is the record.