# Sony ISP breach exposes 2.5 million customer records

> A subsidiary of Sony Network Communications suffered a data breach affecting roughly 2.5 million ISP customers and former users, with personal details and some email passwords exposed.
- Title: Sony ISP breach exposes 2.5 million customer records
- Summary: A subsidiary of Sony Network Communications suffered a data breach affecting roughly 2.5 million ISP customers and former users, with personal details and…
- Keywords: sony network communications, data breach, so-net, ntt docomo, japan, cybersecurity, customer data, isp, technology, Sony, breach, exposes
- Source: TechRadar — https://techradar.com/pro/security/data-breach-at-sony-isp-subsidiary-exposes-2-5-million-customer-records-as-japan-hit-with-another-major-cyberattack
- Published: 2026-10-29T13:05:00+00:00
- Read time: 2 min
- Topics: sony network communications, data breach, so-net, ntt docomo, japan, cybersecurity, customer data, isp, technology
## Sony ISP subsidiary hit by major breach
Sony Network Communications, the Japanese tech giant's Internet Service Provider arm, confirmed a data breach affecting roughly two point five million people including current and former customers.
## What data was stolen
Stolen files included phone numbers, email addresses, and in some cases email passwords. The attackers accessed So-net, the company's consumer-facing ISP service brand.
## Timeline of the attack
The breach happened on Monday, October nineteenth, twenty twenty-six, and was spotted four days later on October twenty-third. Sony immediately shut down the affected server and blocked communications from the source.

> Immediately after confirming the incident, we shut down the affected server and blocked communications from the source of the unauthorized access.
## Scale of exposed records
Investigation determined attackers exfiltrated two million one hundred forty-one thousand nine hundred eighty-six sensitive records.
## Impact on NTT Docomo customers
More than four hundred forty thousand records were taken from plala, S Course, affecting NTT Docomo, a separate internet service provider using Sony Network Communications' underlying infrastructure.

> There is a risk of suspicious communications from those who misuse potentially leaked information in the future.
## Email and banking data compromised
Some So-net members' email addresses and passwords were stolen. Email Service G had twenty-four thousand six hundred fifty-five affected addresses, A-Box had seventeen thousand six hundred seventy-two, So-net VAIO Mail had seven thousand five, and…
## Limited banking information exposed
Sony confirmed the leakage of sixteen records containing bank account information including financial institution name, bank code, branch name, branch code, deposit account type, account number, and account holder's name.Bank account PINs were not compromised.

> We confirmed the leakage of 16 records containing bank account information, including financial institution name, bank code, branch name, branch code, deposit account type, account number, and account holder's name.
## Investigation and no claims yet
Sony Network Communications notified Japan's Personal Information Protection Commission and other relevant government and law enforcement organizations.
## Part of broader Japanese cyberattack wave
The attack comes less than a week after Japanese internet giant GMO Group told customers to scan computers for viruses, back up data, disconnect devices from the internet, and shut them down.
## Key takeaway

Sony Network Communications' ISP subsidiary confirmed a breach of roughly two point five million customer records on October twenty-third, twenty twenty-six, exposing personal details and some email passwords.