Sony Network Communications, a Sony Group subsidiary that provides ISP services in Japan, confirmed a data breach that exposed 2,585,481 customer records. The breach occurred on October 19, was detected four days later, and led the company to shut down the compromised servers and block external communication. Exposed data includes full names, phone numbers, email addresses, user IDs, dates of birth, gender, and Internet Connection IDs; no banking or payment details were leaked. An additional 54,401 email addresses and account passwords were also exposed, prompting the company to advise users to change their passwords. The breach affects 2,141,986 So-net entries and 443,495 plala (S Course) records, the latter impacting NTT Docomo’s Hikari service customers, who have been warned about phishing emails and fake websites. Sony reported the incident to Japan’s Personal Information Protection Commission and is investigating the cause and scope. 1