In Tokyo, a significant breach occurred when hackers exploited a flaw in the email infrastructure managed by KDDI Corporation, affecting 14.22 million email accounts across six Japanese internet service providers. The breach, which was detected and blocked on June 17 but publicly disclosed on June 23, exposed email addresses and passwords, some of which were stored in hashed or encrypted forms. The incident highlights the vulnerability of a shared backend system used by providers such as STNet, JCOM, and BIGLOBE, among others. KDDI urged all affected users to reset their passwords and enable two-factor authentication, acknowledging that the credentials should be considered compromised. The breach also impacted former customers, complicating notification efforts. Although no threat actor has been identified, and no ransom demand has been made, the incident has drawn regulatory attention from Japan’s Personal Information Protection Commission and the Ministry of Internal Affairs and Communications. The investigation continues as the data remains potentially exploitable by cybercriminals.
How Did Hackers Access 14.2 Million Email Accounts in Japan?
