What happened
On October 7, 2026, CrowdStrike disclosed a campaign against several South Korean financial organizations from late September to early October, based on Claude Code session histories, memory files and ARTEX configuration found in open directories on attacker servers.
ARTEX is an automated penetration-testing agent a Chinese developer published on GitHub this year; it has no model of its own and plugs into outside LLMs. Here it used DeepSeek v4.1-flash as its main backend, with GLM-5.3 and Grok 4.6 in separate Claude Code sessions. One bank's loan inquiry service for brokers and another's employee mobile work system were breached, and the attacker went as far as asking Claude to suggest Telegram groups that sell Korean data. CrowdStrike assesses with moderate confidence that the actor is a financially motivated Chinese speaker. President Lee Jae Myung mentioned signs of AI model use at a cabinet meeting on October 6. The ARTEX developer later took the project closed-source.
Why it matters
It is the same structure seen in other campaigns: a public harness wired to a cheap model API. Because the attacker leaked their own working records into open directories, the workflow of an agent-driven attack is visible in detail. Even after the project went closed-source, English and Korean derivatives were already circulating.
What to do now
- Prioritize exposure of auxiliary portals (brokers, partners, employee mobile apps).
- Monitor anomalous use of coding-agent tools from non-corporate IPs and accounts.
- Treat scale figures as varying by outlet — this source does not fix an official victim count.