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Security·1 min read

NTT Docomo Breach Also Exposed ID Document Numbers; Payouts Weighed

NTT Docomo says the breach of My docomo and its online shop, affecting up to 300,000 customers, also leaked ID document numbers. The carrier is weighing compensation.

A smartphone displaying a login screen with a red security warning icon, symbolizing a customer data breach at a mobile carrier.
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NTT Docomo said on November 6 that the unauthorized access to "My docomo" and the "docomo Online Shop" exposed more data than first reported, including identity document numbers. The incident affects up to 300,000 customer records, and the company is considering condolence payments to affected users.

In its first announcement on November 5, Docomo listed names, addresses, dates of birth, mobile phone numbers and contact phone numbers, and described the cause as under investigation. The latest update confirms the cause was unauthorized access by an outside party and widens the list of leaked items.

What was added

For all affected records, the company now adds ID document numbers, contract details such as the contract start date, plan, options and discounts, as well as age and email addresses.

For some customers, further information was also exposed: financial institution name, branch name, account number and account holder name, the names and contact details of legal guardians or authorized agents, workplace or corporate names and addresses, and data related to a child-rearing support program.

Services remain suspended

Docomo detected the unauthorized external access to both sites on November 4 and halted various procedures from around 1:05 a.m. on November 5. It has not said when services will be restored.

The expanded scope matters because ID document numbers and bank account details, combined with names, addresses and contract information, can be used for phishing and identity fraud. Customers should be cautious about unexpected calls, emails or messages that reference their contract or account details.

The condolence payments are still under consideration, and the company has not announced amounts or conditions.

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Tags:ntt docomodata breachmy docomounauthorized accessjapancybersecurity

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