NTT Docomo security incident history
Hacking, data breaches and other security incidents involving NTT Docomo, with related coverage.
Unauthorised access at NTT Docomo exposes customer data for up to 294,839 lines
Impact: Customer information associated with up to 294,839 lines exposed
Unauthorised external access to NTT Docomo's online shop 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, telephone numbers, identity document numbers, contract information and some bank account information. The company suspended the affected services on 5 November, carried out an investigation and recovery work, and considered compensation payments to victims. The ahamo website and some My docomo services resumed on 9 November.
Related reports: 33 · last report →DDoS attack disrupts Japan's NTT Docomo for around 12 hours
Impact: Access to website, portal and some payment services disrupted for around 12 hours
Japan's NTT Docomo was hit by a DDoS attack on 2 January 2025, disrupting access to its website, portal and some payment services for around 12 hours. Core mobile services were not affected.
Related reports: 2 · last report →