immowelt.de Domain Breach Exposure Report

The domain immowelt.de has experienced a significant exposure event, with a high risk score of 95. The primary threat stems from a large volume of historical data breaches (85.7%) and active infostealer logs (14.3%), impacting over 44,000 client accounts and 341 employee accounts. The timeline shows a notable increase in employee-related events starting in January 2026, coinciding with a surge in client-related events in March 2026. Malware families like LummaC2, Rhadamanthys, and Redline are prevalent, suggesting a sophisticated threat actor. The majority of leaked data originates from combolist sources, indicating credential stuffing or reuse attacks targeting login services such as signin.immowelt.de and secure.immowelt.de. The geographical breakdown shows a concentration of activity in Germany, consistent with the domain's origin. Given the high risk score and the substantial number of affected client and employee accounts, this incident warrants immediate attention. The prevalence of infostealer malware and the origin of leaks from combolists highlight a critical risk of account compromise and potential follow-on financial fraud or further data exfiltration. Remediation efforts should focus on immediate credential resets for all affected employees and clients, enhanced monitoring of login activity for suspicious patterns, and a review of authentication mechanisms to prevent future credential stuffing attacks. The timeline indicates a prolonged period of exposure, suggesting that proactive threat hunting and incident response are crucial.