# MAL-2026-11501: Malicious code in simple-date-formatter-util-5 (npm)


- **Type:** Malicious package
- **Package:** `simple-date-formatter-util-5` (npm)
- **Published:** 3 Aug 2026

## What is MAL-2026-11501?

MAL-2026-11501 is a malicious package in simple-date-formatter-util-5, published on 3 Aug 2026. 

### Official description

The package is advertised as a date-formatting utility but its package.json postinstall script curls cloud-provider instance metadata endpoints (AWS 169.254.169.254, Alibaba 100.100.100.200, Tencent metadata.tencentyun.com and 169.254.0.23), retrieves the IAM security-credentials role, captures the output alongside `ls -la /data/`, and POSTs the collected data to attacker-controlled Interactsh (oast.fun) out-of-band subdomains such as safjhdvsfwzhieemkdzbgr54r0yjhrmok.oast.fun/metadata and ycrqyyjhwepdmhjifyccxss1hrks8lcd2.oast.fun/metadata. The tarball also ships postinstall.js, which enumerates ~/.ssh (reading.pub filenames and directory listing) and POSTs the results with username and platform to hardcoded IP 124.221.154.135:443/post over HTTPS. Behavior fires automatically on `npm install`, does not match the declared date-formatter purpose, and results in cloud IAM credential and SSH-context exfiltration to attacker infrastructure.

The OpenSSF Package Analysis project identified 'simple-date-formatter-util-5' @ 1.0.0 (npm) as malicious.

It is considered malicious because:

- The package communicates with a domain associated with malicious activity.

- The package executes one or more commands associated with malicious behavior.

## What should I do about MAL-2026-11501?

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-2026-11501 is a malicious package: simple-date-formatter-util-5 (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-2026-11501/ (Markdown: https://insights.sbomify.com/MAL-2026-11501/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/MAL-2026-11501

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From sbomify Insights: https://insights.sbomify.com/MAL-2026-11501/
Summaries are generated and may contain mistakes; the official description above is the record.