A student at South China University of Technology breached at least seven South Korean financial institutions using ARTEX, a Chinese open-source agentic penetration testing tool, compromising personal data on 68,000 people. The attacker was caught through their own operational failures: they left directory listing enabled on their server, exposing Claude Code session histories, Claude memory files, and ARTEX configurations. Within those sessions, the attacker had asked Claude to write on their resume that they had hacked Korean banks, giving investigators personal identifying information. They also queried Claude about where stolen South Korean data could be sold.
ARTEX was created by Chinese cybersecurity engineer Li Puhua, alias 'Autumn', and has been freely downloadable on GitHub since July. It won the 'Agent+' attack and defense challenge hosted by Baidu in September. The tool can leverage multiple large language models. In this attack, the attacker ran ARTEX on DeepSeek v4.1-Flash via an API reseller and also used GLM-5.3, Grok 4.6, and Claude Code.
CrowdStrike identified an ARTEX instance at IP address 38.244.50[.]120 port 18899, which hosted an open directory containing a Claude Code markdown configuration file. That CLAUDE.md file contained a Chinese-language pentesting prompt specifying how the LLM should conduct penetration testing activities. A threat actor-controlled Hong Kong-based IP address appeared within the discovered configuration document. The actor acquired virtual private server infrastructure at multiple IP addresses for command-and-control operations. Investigators identified ARTEX's involvement by finding its HTML tag signature in command-and-control server headers. Moon Jong-hyun, security center head at South Korean cybersecurity firm Genians, publicly disclosed the findings on LinkedIn.