GMO Cybersecurity by Ierae found ARTEX, an open-source AI pentest tool from China, on attack servers targeting about 20 Japanese companies, campaign by campaign and industry by industry. 8 had already disclosed breaches.
CrowdStrike saw the same tool, with Claude Code sessions, hit Korean banks. The developer stopped work; the forks remain.
https://japancyberwatch.com/articles/artex-ai-pentest-tool-japan-breach-wave-gmo-2026