ARTEX is an open-source tool where AI agents run a penetration test on their own. Since August 2026, state-aligned groups, criminal crews and one runaway research agent have pointed ARTEX at hundreds of organizations. In one case, an agent went from a GitHub search for leaked secrets to stolen cloud data in five minutes. This post covers what ARTEX is, who uses ARTEX, how to spot ARTEX activity, and how you remove its easiest way in.