# MAL-2026-4253: Malicious code in pylogft (PyPI)


- **Type:** Malicious package
- **Package:** `pylogft` (PyPI)
- **Published:** 22 May 2026

## What is MAL-2026-4253?

MAL-2026-4253 is a malicious package in pylogft, published on 22 May 2026. 

### Official description

On `import pylogft`, the package's `__init__.py` (lines 26-27) checks whether the install directory begins with `/Users` or `/Library` (macOS developer/CI hosts) and, if so, spawns `_check.py` as a detached subprocess with stdout/stderr redirected to DEVNULL. `_check.py` then POSTs the installer's resolved package directory (`base_dir`) to `https://pypkg.dev/project/pylogft/json` — a lookalike of pypi.org / pkg.go.dev — with TLS verification explicitly disabled via `ssl._create_unverified_context()`, registering the host with the C2 and leaking filesystem layout (e.g., `/Users/<victim>/...`). The script then polls that endpoint every 60s, base64-decodes the response, and passes the decoded string to `os.system(f"pip show {package_list}")`. The package's `shell_escape` regex permits `;`, `|`, `&`, and `>`, so any C2 response containing those metacharacters breaks out of the `pip show` prefix and executes arbitrary shell commands on the installer's machine. The package advertises itself as a pure-Python logger and has no legitimate reason to poll a remote endpoint, disable TLS, or execute returned payloads. The macOS-only gate, the silenced subprocess output, and the innocuous `_check.py` filename next to legitimate logger modules are evasion layered on top of the backdoor.

Package silently executes remote code during import.

---

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

Campaign: 2026-05-lognest

Reasons (based on the campaign):

 - Downloads and executes a remote malicious script.

## What should I do about MAL-2026-4253?

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-2026-4253 is a malicious package: pylogft (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-2026-4253/ (Markdown: https://insights.sbomify.com/MAL-2026-4253/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/MAL-2026-4253

---
From sbomify Insights: https://insights.sbomify.com/MAL-2026-4253/
Summaries are generated and may contain mistakes; the official description above is the record.