---
id: MAL-2026-10100
title: Malicious code in proxy-check-i (PyPI)
summary: Malicious code in proxy-check-i (PyPI)
severity: none
vendor: proxy-check-i
product: proxy-check-i
ecosystem: pip
affected:
  - proxy-check-i
published: '2026-07-09'
updated: '2026-07-09'
source: OSV
sourceUrl: 'https://osv.dev/vulnerability/MAL-2026-10100'
references:
  - url: 'https://pypi.org/project/proxy-check-i/0.1.0/'
  - url: 'https://pypi.org/project/proxy-check-i/0.1.1/'
tags:
  - osv
  - pip
ingestedAt: '2026-07-10T13:49:11.235Z'
---

## Overview


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

## Source: amazon-inspector (2da390c130eb840eb129a5d43faf0a64a0f0f602070243613aa0e2f8ea8f6d04)
The package advertises itself as a wrapper for a 'qsshd executable' but the bundled Go binary is a reverse-SSH daemon that grants a remote operator persistent shell, exec, pty, and TCP port-forwarding on the installer's host. The entry point `proxy-check-i` (declared in the package's console_scripts, mapped to `qsshd.launcher:main`) uses `os.execv` to launch the bundled Go binary. The daemon establishes device identity by writing a `.device_lock` file under `$XDG_CONFIG_HOME`, `/dev/shm`, or `/tmp`, then repeatedly dials out to a relay via `github.com/mydearniko/overthing` (`tunnel.NewServer` with `RelayURI` and `ForwardAddr` pointing at the local SSH listener). SSH authentication only accepts a single hardcoded ed25519 public key embedded at build time via `//go:embed authorized_keys`, so only the key holder can connect. The reverse-connect design bypasses inbound firewalls. PyPI metadata is a cover story: PKG-INFO summary mentions only 'qsshd executable' with no README and no disclosure of SSH-server, authorized-keys, or outbound-relay behavior, so an installer cannot infer they are enabling a remote-shell daemon. Any host that runs `proxy-check-i` is remotely controllable by the key holder.


## Affected packages

- `proxy-check-i`

## Remediation

Refer to the advisory for the patched release.