On 19 October 2026, GMO Cyber Security by Ierae confirmed that ARTEX was part of the infrastructure used in attacks targeting approximately 20 Japanese companies. Although 8 companies have publicly disclosed information breaches, breaches at all of the targeted companies have not been confirmed.
GMO Cyber Security by Ierae identified traces indicating that ARTEX, an agentic open-source penetration testing tool originating in China, was used in a campaign targeting approximately 20 Japanese companies. Of these, 8 companies publicly disclosed information breaches between September and October, but no evidence supporting breaches at all of the targeted companies has been presented.
ARTEX is an open-source tool developed in China that uses large language models to automate reconnaissance and vulnerability testing. Following reports of attacks in South Korea, it has been suggested that the tool may also have been deployed against servers in Japan between late September and early October.
GMO said the attacks targeted companies by industry and confirmed the presence of AI-enabled servers used maliciously on multiple servers. The company names and details of the leaked data have not been disclosed, but GMO said it had shared information with investigative authorities.
As part of its future response, GMO has provided procedures and checklists for assessing the possibility of damage, and is encouraging stronger defenses based on commonalities among supply chains and business partners.