jcb.co.jp Domain Breach Exposure Report

The domain jcb.co.jp exhibits a high-risk score of 94, primarily driven by a significant volume of historical data breaches (84.6%) and active infostealer logs (15.4%). Over the observed period, there were 30,682 historical data breaches and 5,593 infostealer events. The timeline indicates a notable increase in client-related events, particularly in March 2026, and employee-related events in September 2025 and January 2026. The most prevalent malware families are LummaC2, Rhadamanthys, and Vidar, all associated with credential theft. The data suggests a widespread compromise affecting both clients and employees, with a substantial portion of the exposure originating from combolist sources, indicating potential credential stuffing attacks against services like my.jcb.co.jp. The high risk score and the prevalence of infostealer malware targeting credential harvesting warrant immediate attention. The large number of historical data breaches and active infostealer logs suggest a persistent threat actor or multiple actors actively exploiting vulnerabilities or compromised credentials. Remediation efforts should focus on strengthening authentication mechanisms, such as implementing multi-factor authentication across all services, particularly for employee and client portals like my.jcb.co.jp. A thorough review of security logs for suspicious activity related to the identified malware families and targeted services is also recommended, alongside user education on phishing and credential security best practices.