livedoor.jp Domain Breach Exposure Report

The domain livedoor.jp has experienced a significant exposure event with 800 total recorded incidents over the period of July 2025 to June 2026. The majority of these events, 694 (86.8%), are classified as historical data breaches, while 106 (13.3%) are active infostealer logs. The timeline shows a notable increase in client-related incidents from August 2025 onwards, peaking in April 2026 with 171 client exposures. Employee-related incidents also saw a surge in September 2025 and April 2026. Malware families associated with these events include Redline, LummaC2, Acreed, and Raccoon, indicating potential credential harvesting and unauthorized access. The primary sources of leaked data appear to be combolist sources (92.5%) and database dumps (7.5%). Given the high volume of historical data breaches and the presence of active infostealer logs, this exposure poses a substantial risk to both employees and clients of livedoor.jp. The prevalence of combolists suggests that credentials previously compromised in other incidents may be reused against this domain. The focus for remediation should be on immediate credential rotation for all affected users, enhanced monitoring for suspicious login activity, and a thorough review of data security practices to prevent future data breaches. The identified malware families necessitate endpoint security reviews and potential incident response actions.