# MAL-2026-18299: Malicious code in claudeopuseni (PyPI)


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

## What is MAL-2026-18299?

MAL-2026-18299 is a malicious package in claudeopuseni, published on 25 Oct 2026. 

### Official description

On import, claudeopuseni/__init__.py invokes _boot.check(), which issues an HTTPS GET to https://thisisafalsepositive.st/cdn/v2/claudeopuseni/manifest.json, reads field 'r' as an encrypted blob (falling back to the base64-encoded _payload.PAYLOAD bundled in _payload.py when the host is unreachable), decrypts it with a ChaCha20+HMAC routine in security.unsign keyed from sha256(b'claudeopuseni.2026.channel.v1'), and passes the plaintext to builtins.exec via an attribute name assembled from chr(101,120,101,99) to hide the sink from static scanners. _boot gates detonation on the presence of a real user profile (USERPROFILE/HOME containing Documents or Downloads) and on absence of DAS_STAGED=1 or claudeopuseni_TELEMETRY=0, and caches a timestamp to suppress re-execution within 6 hours — a sandbox/CI evasion wrapper. The embedded fallback blob guarantees execution of attacker-controlled code even when the remote host is unavailable. The resulting code runs with the importing developer's privileges on any machine that imports the package in a normal user environment. The package name resembles the Anthropic Claude product family, consistent with a typosquat lure.

During installation, obfuscated code is used to fetch code hidden in an image containing a Python application with a native extension module. This module holds an obfuscated infostealer which collects sensitive data and exfiltrates them to a C2 server retrieved from transaction history in the Polygon blockchain.

---

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

Campaign: 2026-09-donutautosellsrc

Reasons (based on the campaign):

 - infostealer

 - Downloads and executes a remote executable.

 - obfuscation

 - The package contains code to detect if it is running in a sandbox environment.

 - malware

 - native-extension

 - steganography

 - c2-in-blockchain

## What should I do about MAL-2026-18299?

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-2026-18299 is a malicious package: claudeopuseni (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-2026-18299/ (Markdown: https://insights.sbomify.com/MAL-2026-18299/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/MAL-2026-18299

---
From sbomify Insights: https://insights.sbomify.com/MAL-2026-18299/
Summaries are generated and may contain mistakes; the official description above is the record.