Cybersecurity Alert: NTT Communications Faces Major Data Breach
Japanese telecommunications leader NTT Communications Corporation has alerted approximately 18,000 business clients about a cybersecurity incident that has compromised sensitive customer information. This breach, which came to light in early February 2025, infiltrated the company’s Order Information Distribution System, holding contractual data from nearly 17,900 corporate accounts.
Investigations revealed unauthorized access to NTT’s systems on February 5, with evidence of potential data leakage confirmed the following day. The compromised database included critical information, such as customer names, representatives’ names, contract numbers, phone numbers, email addresses, physical addresses, and details regarding service usage. Uniquely, contracts involving corporate smartphones and mobile services from NTT Docomo were not impacted by this breach.
In response to the incident, NTT swiftly cut off the hacker’s access by February 6. However, on February 15, further investigations revealed that the attackers had extended their reach to another network device. The intrusion was expediently contained by disconnecting the affected device, and NTT is now confident that the threat has been fully mitigated.
In a notable departure from standard practice, NTT chose not to individually notify affected clients, opting instead for a public announcement via its website. This decision highlights a growing trend among corporations to manage breach communications through broader announcements rather than direct alerts to impacted stakeholders.
This incident marks yet another chapter in NTT’s ongoing battle with cybersecurity threats. Earlier in January 2025, the company endured a significant 12-hour Distributed Denial of Service (DDoS) attack that severely disrupted its mobile services and payment platforms. Additionally, in May 2020, attackers breached NTT’s internal network, compromising sensitive information from numerous clients.
As one of Japan’s largest telecommunications providers, NTT remains an attractive target for cybercriminals, necessitating ongoing enhancements in its cybersecurity framework. This recent breach underscores the importance of robust security measures and adherence to best practices to safeguard corporate infrastructure.
In evaluating the tactics that may have been employed during this incident, a look at the MITRE ATT&CK framework reveals potential use of techniques such as initial access, privilege escalation, and persistence. These frameworks provide a valuable perspective on the underlying strategies that adversaries may deploy in cyberattacks, emphasizing the necessity for vigilance and proactive defense mechanisms.
As NTT bolsters its cybersecurity measures in light of these events, businesses worldwide can draw lessons from this incident, reaffirming the critical need for enhanced security protocols in an increasingly volatile digital landscape. As cyber threats continue to evolve, so must the tactics used to combat them.
