# MAL-2025-191861: Malicious code in s3transfer-sl (PyPI)


- **Type:** Malicious package
- **Package:** `s3transfer-sl` (PyPI)
- **Published:** 23 Apr 2025

## What is MAL-2025-191861?

MAL-2025-191861 is a malicious package in s3transfer-sl, published on 23 Apr 2025. 

### Official description

During installation, the package attempts to exfiltrate env variables and tokens from Azure metadata API. It's a malicious clon of s3transfer

---

Category: MALICIOUS - The campaign has clearly malicious intent, like infostealers.

Campaign: 2025-04-s3transfer-sl

Reasons (based on the campaign):

 - exfiltration-cloud-tokens

 - clones-real-package

 - typosquatting

## What should I do about MAL-2025-191861?

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-2025-191861 is a malicious package: s3transfer-sl (PyPI). 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-2025-191861/ (Markdown: https://insights.sbomify.com/MAL-2025-191861/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/MAL-2025-191861

---
From sbomify Insights: https://insights.sbomify.com/MAL-2025-191861/
Summaries are generated and may contain mistakes; the official description above is the record.