proxy-check-i

Details

**Severity:** Critical

**Affected versions:** `= 0.1.0`

## 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.

## Source: kam193 (dd01be5624206ed8c0a5ba9535c9a9e79ed8770b37eb9ebc381edbe73cb5e779)
The embedded binary starts a relayed SSH-like server using a hardcoded authorized_key. Thanks to using a relay network, the attacked does not need to directly expose ports from the machine.


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


Campaign: 2026-07-proxy-check-i


Reasons (based on the campaign):


 - backdoor


 - The package contains code to execute remote commands (probably limited to a specific set) on the victim's machine.

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Credit: [OpenSSF](https://github.com/ossf/malicious-packages) ([source](https://github.com/ossf/malicious-packages/blob/49d0cfba3689ed9b195d101d3a2a964c6a77f767/osv […]

**References:**
- https://bad-packages.kam193.eu/pypi/package/proxy-check-i
- https://github.com/ossf/malicious-packages/blob/49d0cfba3689ed9b195d101d3a2a964c6a77f767/osv/malicious/pypi/proxy-check-i/MAL-2026-10100.json
- https://pypi.org/project/proxy-check-i/0.1.0
- https://pypi.org/project/proxy-check-i/0.1.1
- https://github.com/advisories/GHSA-hgmc-ffc9-pqfh

Compromised versions (1)

• = 0.1.0

Any computer that installed or ran a compromised version should be considered fully compromised. Rotate every secret on that machine from a clean environment.