Unauthorized access at NTT Docomo exposes customer data for up to 294,839 lines
Unauthorized external access to NTT Docomo's online store and My docomo exposed customer information associated with up to 294,839 lines. The attacker exploited the way multiple systems were interconnected to query and obtain information in bulk, with the exposed data including names, addresses, dates of birth, phone numbers, identity document numbers, contract information and some bank account information. The company suspended the affected services on November 5, conducted an investigation and recovery work, and considered compensation payments to victims. The ahamo website and some My docomo services resumed on November 9.
Key facts
- Affected organization
- NTT Docomo
- Incident type
- Data breach
- Occurred / detected
- 2026-11-05
- Scale of damage
- Customer information associated with up to 294,839 lines exposed
- Cause / method
- Unauthorized external access exploiting interconnected systems to query and obtain customer information in bulk
- Location
- Japan
If your data was exposed
Exposed dataNameAddressDate of birthPhone numberBank account
- Don’t tap links in texts, calls or emails that mention this incident and offer compensation, refunds or breach checks. Check directly on the organization’s official website or app.
Timeline
- Various My docomo and online store operations were suspended from around 1:05 a.m. due to possible unauthorized external access.
- The company explained the exposure of customer information associated with up to 294,839 lines and the attack method exploiting interconnected systems, and considered compensation payments.
- The ahamo website and some My docomo services resumed following emergency checks.
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Other incidents at NTT Docomo
DDoS attack disrupts Japan's NTT Docomo for about 12 hours
Impact: Access to website, portal and some payment services disrupted for about 12 hours
Japan's NTT Docomo was hit by a DDoS attack on January 2, 2025, disrupting access to its website, portal and some payment services for about 12 hours. Core mobile services were not affected.
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The summary and key facts are written by AI from related reports and may contain errors. Check the original articles and the organization’s official statements for accurate details.