GMOサイバーセキュリティ confirmed the use of ARTEX in unauthorized access attacks targeting Japanese companies. Approximately 20 companies were targeted, and 6 additional AI-powered attack infrastructure nodes were identified. Other companies have also disclosed data breaches in separate incidents.
GMOサイバーセキュリティ byイエラエ announced that its investigation of attacker infrastructure targeting Japanese companies had confirmed the use of ARTEX, an AI-powered automated tool. Approximately 20 companies were targeted through the initial attack infrastructure, suggesting that the attacks may have been concentrated in the same industries.
A further investigation identified 6 AI-powered attack infrastructure nodes primarily targeting Japanese companies. The targets included companies in digital gifts, education and printing, points and gifts and marketing, insurance and finance, and e-commerce, media and logistics.
Of the targeted companies, 8 had already disclosed data breaches in September–October 2026, raising suspicions that the impact may have spread through attacks by the same group. This does not mean that all approximately 20 companies were simultaneously confirmed to have been successfully compromised.
ARTEX is described as an open-source AI tool for automated intrusion and testing developed in China. Traces of the tool have also been identified in a separate case targeting financial institutions in South Korea. The incidents in Japan indicate that ARTEX has also been used in attack infrastructure targeting Japanese companies.