# MAL-2026-12403: Malicious code in node-cache-multithread (npm)


- **Type:** Malicious package
- **Package:** `node-cache-multithread` (npm)
- **Published:** 5 Aug 2026

## What is MAL-2026-12403?

MAL-2026-12403 is a malicious package in node-cache-multithread, published on 5 Aug 2026. 

### Official description

index.js, the package's declared main entry, is a ~23KB obfuscator.io RC4/base64 string-array bundle whose top-level IIFE runs on require(). It requires fs, os, path, child_process, and an HTTP client; builds a hardcoded remote URL from four numeric octets and a port (concealed inside the 314-entry string array); fetches a payload; splits the response into IV and ciphertext on ':'; decrypts with a hardcoded key via crypto.createDecipheriv; writes the plaintext to a file under os.tmpdir(); and spawns/execs it through child_process with windowsHide:true. The package advertises itself in the README as `@array-util/nodepull` while publishing under the name `node-cache-multithread`, so a developer following the README will install/require a differently-named tarball whose only shipped file is the dropper. No cache/library functionality is present.

## What should I do about MAL-2026-12403?

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-2026-12403 is a malicious package: node-cache-multithread (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-2026-12403/ (Markdown: https://insights.sbomify.com/MAL-2026-12403/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/MAL-2026-12403

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From sbomify Insights: https://insights.sbomify.com/MAL-2026-12403/
Summaries are generated and may contain mistakes; the official description above is the record.