January 4, 2025 – NTT Docomo, Japan’s largest mobile communications operator, announced that it had suffered a cyberattack on Thursday, resulting in temporary disruptions to some of its services. The company stated that it is currently striving to restore normal operations.
According to NTT Docomo’s statement, the company’s systems were targeted by a Distributed Denial-of-Service (DDoS) attack. This type of attack floods the network with overwhelming amounts of junk traffic, rendering some services temporarily inaccessible.
From early Thursday morning until late afternoon, NTT Docomo users encountered difficulties accessing news websites, video streaming platforms, mobile payments, webmail services, and a golf enthusiast website. The company reported that most services have been restored; however, some content updates may still experience delays.
At present, NTT Docomo has not attributed the incident to any specific hacker group.
NTT Docomo is the latest victim in a series of recent cyberattacks targeting Japanese companies. In early December, Japan Airlines (JAL) reported flight delays due to a suspected DDoS attack that caused a “surge in traffic” on their systems.
Last month, Sumitomo Mitsui Insurance, a leading Japanese insurance company, disclosed that a ransomware attack on a third-party supplier may have exposed the personal information of thousands of policyholders.
In October, the Japanese watchmaker Casio warned customers of potential delivery delays due to a ransomware attack, which was claimed by the Underground gang.
Other Japanese companies that have recently fallen victim to cyberattacks include the motor manufacturer Nidec, the automotive parts manufacturer Yorozu, and the research institution Monohakobi.
Additionally, major Japanese financial institutions such as Mitsubishi UFJ Bank, Resona Bank, and Mizuho Bank have experienced disruptions to their online banking services due to suspected cyberattacks.
