# MAL-2026-1263: Malicious code in python-module-installer (PyPI)


- **Type:** Malicious package
- **Package:** `python-module-installer` (PyPI)
- **Published:** 6 Mar 2026

## What is MAL-2026-1263?

MAL-2026-1263 is a malicious package in python-module-installer, published on 6 Mar 2026. 

### Official description

The package clones a legitimate webdavclient3 library and modifies it to be an installer utility. During installation, the package exfiltrates the current working directory to a remote WebDAV server or Telegram Bot. Additionally, the package targets cryptocurrency operations in another suspicious project, https://github.com/fewcatltd/zkSync/

The install_modules() method injects code into two files, which are characteristic for this repository, and causes exfiltrating configuration files during cryptocurrency exchange operations.

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

Campaign: 2026-03-old-python-module-installer

Reasons (based on the campaign):

 - impersonation

 - dependency-confusion

 - files-exfiltration

 - action-hidden-in-lib-usage

 - clones-real-package

 - crypto-related

 - exfiltration-crypto

## What should I do about MAL-2026-1263?

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-2026-1263 is a malicious package: python-module-installer (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-2026-1263/ (Markdown: https://insights.sbomify.com/MAL-2026-1263/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/MAL-2026-1263

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From sbomify Insights: https://insights.sbomify.com/MAL-2026-1263/
Summaries are generated and may contain mistakes; the official description above is the record.