Sony Network Communications has reported a data breach that involves around 2.6 million records having present as well as previous customers’ personal details. A Sony Group Corporation subsidiary, the organization supplies telecommunications and technology services operating as an Internet service provider (ISP) in Japan.

The cyberattackers accessed the So-net member database on October 19,2026. The organization detected the unauthorized access four days later. The former immediately took the affected server online and blocked traffic emanating from the hackers.

By October 24th, the organization’s team confirmed that personal data had been leaked and found out the scope of the data breach. The stolen data contains names, birth dates, gender, phone numbers, email addresses, user IDs and the IDs clients utilize to connect to the Internet. Around 2.14 million exposed records are of So-net subscribers and 443,000 to Plala (S Course) subscribers.

For your information the cyberattackers also obtained around 54,000 email addresses, along with their passwords, belonging to 4 additional mail services: Mail Service (G), A-Box, So-net VAIO Mail, and the PostPet email account service. So-net has not identified any password leak for the free basic mailbox that comes with a subscription.

On October 27, 2026 the company started the process of resetting the passwords for the impacted email addresses, forcing users to set new ones before they could resume using the services.

“Due to the leak of email addresses and email address passwords, a third party who obtained the information was in a position to view, send, and receive emails using email software and So-net Webmail. We implemented these measures as an emergency step to prevent unauthorized use of customers’ email addresses,” reads a translation of an FAQ issued by So-net.

Malicious actors can misuse the stolen personal data of customers to impersonate the company. Customers are advised to treat messages, emails and calls claiming to be from the company with caution. They may become victims of phishing campaigns orchestrated by malicious entities.

SOURCES:-

https://www.securityweek.com/hackers-steal-2-6-million-records-from-sonys-japanese-isp-so-net/

https://www.helpnetsecurity.com/2026/10/28/sony-network-communications-data-breach-so-net/

https://www.esecurityplanet.com/threats/news-sony-so-net-data-breach-apac-japan/

https://www.bleepingcomputer.com/news/security/sony-isp-subsidiary-data-breach-exposes-25-million-customer-records/

https://www.govinfosecurity.com/sony-isp-breach-exposes-26-million-user-records-a-33245