gungho.jp Domain Breach Exposure Report

The telemetry indicates a significant exposure event impacting gungho.jp, with 4789 total events observed over the period. The majority of these events, 84.7%, are historical data breaches, and 15.3% are active infostealer logs. The data breaches primarily originate from "Combolist sources" (98.8%), suggesting compromised credentials. Infostealer activity is linked to malware families such as Redline (16.7%), LummaC2 (14.6%), and Acreed (9.3%), which are known to exfiltrate sensitive information. The targeted services are predominantly related to the "member.gungho.jp" domain, indicating a focus on user authentication credentials. The timeline shows a surge in client-related events in March 2026, with a notable increase in employee-related events in September 2025 and January 2026. This exposure presents a high risk due to the large volume of historical data breaches and active infostealer activity, potentially leading to account takeovers and further compromise. The prevalence of "Combolist sources" suggests that user credentials may have been exposed elsewhere and are being actively tested against gungho.jp services. Remediation should focus on immediate credential reset campaigns for affected users, enhanced monitoring for suspicious login activity on "member.gungho.jp", and strengthening authentication mechanisms to mitigate the impact of credential stuffing attacks.