Sony Network Communications Exposes Data of 2.58 Million Users in So-net and Plala Breach
Sony Network Communications has confirmed a significant data breach impacting over 2.58 million customers of its So-net and plala internet services, exposing personal details and email account credentials.
Sony Network Communications has disclosed a major data breach affecting 2,585,481 customer records from its So-net and plala (S Course) internet services. The incident, which came to light on October 27, 2026, involved unauthorized access to a member database. The breach compromised contact details, account identifiers, and credentials for a subset of email accounts, impacting both current and former subscribers.
The exposed information includes names, telephone numbers, email addresses, user IDs, dates of birth, gender, and internet connection IDs for the affected customers. While main membership account passwords were not compromised, and credit card information was not involved, the breach did expose credentials for 54,401 email accounts across four Sony services: Mail Service (G), A-Box, So-net VAIO Mail, and PostPet Mail. Sony has since reset these affected passwords to prevent further misuse.
In addition to the email account credentials, the breach also led to the exposure of 16 bank account records, containing details such as bank names, branch information, account numbers, and account holder names. However, bank PINs were not stored. Furthermore, seven records involving password reset notification documents were also compromised, prompting password resets for those individuals.
The unauthorized access to the member database occurred on October 19. Sony's internal security team identified the intrusion on October 23, subsequently stopping the affected servers and blocking communications from the source. Investigators confirmed the data leak and identified the categories and counts of affected data by October 24. The company has reported the incident to Japan’s Personal Information Protection Commission.
Sony has not yet disclosed the specific method of entry, whether a software flaw was exploited, or the identity of the attackers. The investigation into the root cause and the full extent of the breach is ongoing. The company has assured that no information leak involving its NURO service or other unrelated services has been confirmed.
This incident is distinct from a previous Sony MOVEit data breach that affected Sony Interactive Entertainment, and no connection between the two events has been established. The affected records include a substantial number of former So-net and plala members who canceled their services from March 2026 onward.
Sony is advising customers to remain vigilant against phishing attempts, urging them to directly access official account websites, reset passwords for affected email accounts, and avoid clicking on suspicious links or opening unexpected attachments. While no secondary harm has been confirmed as of October 27, the company warns that customers may receive suspicious communications.