# MAL-2026-18271: Malicious code in fontus (PyPI)


- **Type:** Malicious package
- **Package:** `fontus` (PyPI)
- **Published:** 25 Oct 2026

## What is MAL-2026-18271?

MAL-2026-18271 is a malicious package in fontus, published on 25 Oct 2026. 

### Official description

Analysis of fontus 0.0.3 on PyPI did not identify any code paths that exfiltrate installer data, execute attacker-controlled payloads at install or import time, relay caller-supplied data to third-party destinations, distribute live credentials, or establish persistence. No install-time network fetches, no lifecycle shell execution, no reads of credential paths (~/.aws, ~/.ssh, ~/.npmrc, browser profiles), and no obfuscated or dynamic-exec patterns were observed.

The package most likely performs fingerprinting by exfiltrating basic information and available fonts, with no other functionality.

---

Category: PROBABLY_PENTEST - Packages looking like typical pentest packages, but also anything that looks like testing, exploring pre-prepared kits, research & co, with clearly low-harm possibilities.

Campaign: 2026-10-fontus

Reasons (based on the campaign):

 - The package contains code to exfiltrate basic data from the system, like IP or username. It has a limited risk.

## What should I do about MAL-2026-18271?

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-2026-18271 is a malicious package: fontus (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-2026-18271/ (Markdown: https://insights.sbomify.com/MAL-2026-18271/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/MAL-2026-18271

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From sbomify Insights: https://insights.sbomify.com/MAL-2026-18271/
Summaries are generated and may contain mistakes; the official description above is the record.