---
id: "CMP-202611-nvoxcm"
kind: "campaign"
aliases: []
title: "cPGuard server security software update channel hijacked: attackers pushed a backdoor that steals root password hashes, SSH keys and cloud tokens (OPSSHIELD confirms)"
severity: "critical"
cvss: null
epss: null
exploited: true
status: "open"
category: "vendor"
products: [{"name": "cPGuard", "fixed": ["5.88.25"], "vendor": "OPSSHIELD", "versions": ">=5.88.12 <=5.88.19"}]
ecosystems: []
tags: ["campaign", "early-warning"]
not_affected_if: []
published_at: null
first_seen_at: "2026-11-02T23:46:44+00:00"
updated_at: "2026-11-02T23:46:44+00:00"
sources: [{"source": "analyst", "url": null, "first_seen_at": "2026-11-02T23:46:44+00:00"}]
---

# cPGuard server security software update channel hijacked: attackers pushed a backdoor that steals root password hashes, SSH keys and cloud tokens (OPSSHIELD confirms)

OPSSHIELD, maker of the cPGuard security plugin for cPanel, DirectAdmin and other hosting control panels, told customers on 2 Nov 2026 that an unidentified attacker got into its licensing and update systems and pushed a malicious script to customer servers through the normal cPGuard update channel. The script runs as root. It plants a backdoor shell, collects /etc/shadow password hashes and other credentials into an archive (loot.tgz), and sends the data to an endpoint on OPSSHIELD's own licensing server through a compromised account. Affected releases are reported as 5.88.12 to 5.88.19. One customer's logs show the update to 5.88.12 followed in the same second by reads of /root/.ssh/authorized_keys and private keys. Distribution has stopped and 5.88.25 removes the known backdoor. The start date, the number of servers that ran the script and how the attacker got in are all unknown. The vendor notice has been reposted by customers on r/netsec, the DirectAdmin forum and Portal do Host.

_Summary, check and fix written by a model from the sources; labelled as such._

## Affected

- :cPGuard affected ? fixed 5.88.25

## How to check

Run cpgcli --version on every server that has cPGuard. Versions 5.88.12 to 5.88.19 are affected. Look for /var/tmp/.cpg91511_sh (the backdoor shell) and the /var/tmp/.cpg91511 directory, including loot.tgz. In cPGuard logs, look for 'software_update.php start as root' / 'Successfully updated to 5.88.12' followed by access to /root/.ssh. Check for unknown keys in /root/.ssh/authorized_keys. The attacker's IPs and domains are unknown (the stolen data went to OPSSHIELD's licensing server).

## Fix

Run cpgcli update --start on every cPGuard server and confirm that cpgcli --version shows 5.88.25. If the update fails, contact OPSSHIELD support. If the script may have run, treat the server as compromised. From a trusted recovery environment, reset passwords for root and all local accounts. Rotate database passwords, S3 access keys, DigitalOcean tokens and any secrets in root's shell history. Replace SSH keys under /root/.ssh and remove their old public keys from every system that trusts them. Do this even if the update succeeds.

## Timeline

- 2026-11-02T23:46:44+00:00 analyst

## Documents

- [describes] r/netsec: CPGuard / OPSSHIELD LLP Breach https://www.reddit.com/r/netsec/comments/1xmcr4e/cpguard_opsshield_llp_breach/
- [describes] CPguard got hacked.. (OPSSHIELD customer notice reposted, DirectAdmin Forums) https://forum.directadmin.com/threads/cpguard-got-hacked.82860/

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_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_