July 18, 2025 Measures (Guidance) to Protect the Secrecy of Communications to Internet Initiative Japan Inc. (hereinafter referred to as the "Company")

　Today, the Ministry of Internal Affairs and Communications (MIC) issued written administrative guidance to the Company, with President, Representative Director, and Executive Officer TANIWAKI Yasuhiko, concerning the leakage of confidential communications at the Company. The document requests that the Company take all necessary measures to ensure the protection of the secrecy of communications and to prevent recurrence.

Note: The published materials are in Japanese only.

1. Background, and other details

　The Company reported that its corporate email hosting service, the IIJ Secure MX Service (hereinafter referred to as the "Service"), was subject to unauthorized external access from August 3, 2024 to April 17, 2025, resulting in an information leakage (hereinafter referred to as the "Incident").
　The Incident was caused by the exploitation of an unknown vulnerability in the software used in one of the external connection servers for the Service. In response, the Company will implement several preventive measures to strengthen its defenses against unknown vulnerabilities and to improve its ability to detect unauthorized access at an early stage.

2. Details of measures

　Since the Incident constitutes leakage of confidential communications as stipulated in Article 4, Paragraph 1 of the Telecommunications Business Act (Act No. 86 of 1984), the MIC issued written guidance to the Company today, requesting thorough implementation of preventive measures and initiatives to promote cybersecurity improvements across the industry.

　The MIC will continue to provide necessary guidance and supervision to ensure the protection of the secrecy of communications.