# MAL-2026-13834: Malicious code in thundertiger (npm)


- **Type:** Malicious package
- **Package:** `thundertiger` (npm)
- **Published:** 12 Aug 2026
- **Also known as:** GHSA-j7j3-pvfq-ph94

## What is MAL-2026-13834?

MAL-2026-13834 is a malicious package in thundertiger, published on 12 Aug 2026. 

### Official description

The package's only shipped content is a single HTML file that mimics a Cloudflare 'Just a moment...' security challenge. The inline script is obfuscated with an obfuscator.io-style shuffled string-array + hex identifier decoder and anti-debug console overrides. After a 1-second delay it assembles a hostname from split literals ('gin.microc' + 'loud.homes' → login.microcloud.homes), forwards the current URL's query string, and calls window.location.replace to redirect the browser to that external host. package.json declares no lifecycle scripts and `main` points at HTML rather than a loadable JS module, so installing or requiring the package does not directly execute the payload against a developer's machine — the harm is directed at end users who load the hosted HTML, using the npm registry as a CDN for a phishing kit. This is registry/namespace abuse rather than a direct installer-side attack; recommend human review to confirm and to coordinate takedown with the registry.

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-2026-13834?

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-2026-13834 is a malicious package: thundertiger (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-2026-13834/ (Markdown: https://insights.sbomify.com/MAL-2026-13834/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/MAL-2026-13834

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From sbomify Insights: https://insights.sbomify.com/MAL-2026-13834/
Summaries are generated and may contain mistakes; the official description above is the record.