The Active Cyber Defense Act has finally taken effect, allowing police and the Self-Defense Forces to take neutralization measures to erase malicious programs. The response to attacks targeting government agencies, defense and critical infrastructure has been strengthened, while reporting requirements for private-sector companies and the government's reporting obligations have been made mandatory.
The Active Cyber Defense Act took effect on 1 October 2026, shifting the country from a passive posture that responds after an attack to one that takes preventive action when signs of an attack emerge. Prior approval from the Cyber Communications Information Oversight Commission is generally required for implementation. The government will be able to access servers identified as the source of attacks and take neutralization measures to remove malicious programs.
The private sector is also affected. IT product reporting will be mandatory for 258 companies in 15 critical-infrastructure industries by March 2027, and companies will be required to report cyberattacks to the government. The trigger is not the occurrence of actual harm but the detection of unauthorized communications, making the establishment of log management and continuous monitoring an urgent priority. A public-private cyber council was launched on the effective date. A system for analyzing attack servers is scheduled to become fully operational in autumn 2027.
Investment in defense, government agencies and infrastructure is expected to gather pace. The Ministry of Defense's FY2027 budget request is ¥8.8908 trillion, among the largest ever, and some expect it to grow to around ¥10 trillion over time. The Ministry of Defense and the Self-Defense Forces plan to expand their specialist cyber units to approximately 4,000 personnel, signaling an intention to incorporate the full-scale operation of active cyber defense.
This article selects 20 TSE-listed stocks likely to benefit from policy support for cybersecurity, focusing on their links with defense, government agencies and critical infrastructure. FFRIセキュリティ and NEC are among those featured, alongside stocks spanning a broad range of fields, including domestic technology, OT security and government cloud services.