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

Malicious package Published
Package
s3transfer-sl
Registry
PyPI

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.

Sources

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