NTT Docomo Confirms Breach of Up to 300,000 Customer Records

What was exposed

The leaked data includes names, addresses, dates of birth, mobile phone numbers and contact phone numbers. Docomo is still checking the details and says it will contact affected customers once they are identified.

Emergency maintenance to address the problem is continuing, and no end time has been set. The company says it has not confirmed any further leakage since the measures were taken. It is still investigating the cause of the breach, the intrusion route, and the exact scope and number of records exposed.

What customers should do

Docomo warns that suspicious emails, SMS messages or phone calls impersonating Docomo or related parties may reach users. It urges people not to access links or open files in such messages.

Because the exposed data combines names, birth dates and phone numbers, it could be used to make fraudulent messages look more convincing, which is why the warning matters for customers even though the figures are not yet final. Docomo says it will notify affected users directly as the investigation progresses.