Prime Minister Takashi ordered rapid government action to counter potential cyber-attacks using Anthropic’s new AI model, Claude Mythos [1].

The move highlights growing fears that advanced AI can discover system vulnerabilities that humans miss and generate code for attacks [1]. Because these capabilities could be weaponized against banks and essential services, the Japanese government is treating the development as a critical security risk [1].

Finance Minister Satsuki Katayama will lead the response by establishing a joint public-private working group [1]. This group will include representatives from the financial industry, IT companies, the government, and the Bank of Japan [2].

Katayama said she expects the group to deepen discussions at the practitioner level to ensure a common understanding of the threats posed by advancing AI technology [2]. The collaboration aims to develop concrete countermeasures to protect the nation's financial stability and infrastructure from AI-driven exploits [1].

Parallel to the Japanese government's concerns, the U.S.-based developer Anthropic has faced its own security challenges. A spokesperson for the company said Anthropic is investigating an incident involving unauthorized access to the Mythos model [3]. According to reports, this unauthorized access occurred on the 21st of the month [4].

The intersection of a powerful new tool and a reported security breach has accelerated the timeline for Japan's regulatory response. The government is now prioritizing the creation of a defensive framework that can evolve as quickly as the AI models themselves [1].

“Claude Mythos can discover system vulnerabilities that humans miss and generate code for attacks.”

The Japanese government's urgent response signals a shift from treating AI as a productivity tool to viewing it as a dual-use weapon. By involving the Bank of Japan and private IT firms, Tokyo is acknowledging that traditional cybersecurity protocols are insufficient against AI that can autonomously identify and exploit zero-day vulnerabilities in real-time.