# MAL-2026-10079: Malicious code in vybscan-testbed-obfuscated-postinstall (npm)


- **Type:** Malicious package
- **Package:** `vybscan-testbed-obfuscated-postinstall` (npm)
- **Published:** 9 Jul 2026
- **Also known as:** GHSA-43r2-4jr2-rhjf

## What is MAL-2026-10079?

MAL-2026-10079 is a malicious package in vybscan-testbed-obfuscated-postinstall, published on 9 Jul 2026. 

### Official description

package.json declares a postinstall lifecycle script that runs `node -e "eval(Buffer.from('<base64>','base64').toString())"`. Installing the package triggers execution of code that is not visible in the package source and is only materialized at install time by decoding an opaque literal. In this specific version the decoded blob is an inert console.log, but the mechanism — obfuscated-then-eval'd bytes wired into a lifecycle hook — is the canonical install-time remote-code-execution shape and has no legitimate use: it lets whoever controls the package substitute arbitrary code at install without changing readable source. The package's self-description as a testbed fixture does not neutralize the pattern; the same install-time hook would execute whatever bytes were placed in the base64 literal.

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-2026-10079?

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-2026-10079 is a malicious package: vybscan-testbed-obfuscated-postinstall (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-2026-10079/ (Markdown: https://insights.sbomify.com/MAL-2026-10079/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/MAL-2026-10079

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From sbomify Insights: https://insights.sbomify.com/MAL-2026-10079/
Summaries are generated and may contain mistakes; the official description above is the record.