---
id: MAL-2026-18299
title: Malicious code in claudeopuseni (PyPI)
summary: Malicious code in claudeopuseni (PyPI)
severity: critical
exploited: true
vendor: claudeopuseni
product: claudeopuseni
ecosystem: pip
affected:
  - claudeopuseni
published: '2026-10-25'
updated: '2026-10-26'
sourceUpdated: '2026-10-26T06:45:15.072389104Z'
source: OSV
sourceUrl: 'https://osv.dev/vulnerability/MAL-2026-18299'
references:
  - url: >-
      https://www.virustotal.com/gui/file/d03c42c275f0dbc617428441508c49ae1adcbbc95af4eeb094bca4e4f8943f3e/detection
  - url: 'https://polygonscan.com/address/0x9c0a507300fd902787bb193d80fca5ce6e1bff9a'
  - url: 'https://bad-packages.kam193.eu/pypi/package/claudeopuseni'
  - url: 'https://pypi.org/project/claudeopuseni/0.1.1/'
  - url: 'https://pypi.org/project/claudeopuseni/0.1.0/'
tags:
  - osv
  - pip
  - malware
ingestedAt: '2026-10-26T12:01:30.295Z'
---

## Overview


---
_-= Per source details. Do not edit below this line.=-_

## Source: amazon-inspector (715421a3b919f086db6ad4a57d6c8d6d333b019e3a63e607be95cf3fcb7aef5d)
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.

## Source: kam193 (355cfc006ca4cb062c248bf2108be828c6164ae20d12ee5c7794ab68ee351843)
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


## Affected packages

- `claudeopuseni`

## Remediation

Refer to the advisory for the patched release.