blesk.cz Domain Breach Exposure Report

The domain blesk.cz has experienced a significant number of data breach events, totaling 4581 over the observed period, with an additional 561 infostealer events. These events primarily involve historical data breaches and active infostealer logs, impacting 193 employees and 4949 clients. The timeline indicates a surge in client-related events from September 2025 onwards, peaking in March and April 2026. Malware families such as LummaC2, Redline, and Rhadamanthys are frequently observed, suggesting potential credential harvesting and data exfiltration activities. The majority of leak repository classifications point to "Combolist sources," indicating a high likelihood of compromised credentials being traded or sold. The high volume of data breaches and infostealer activity, coupled with the prevalence of credential-harvesting malware, presents a critical risk to the organization and its users. The focus should be on immediate remediation of identified vulnerabilities, enhanced monitoring for suspicious activity, and comprehensive user education regarding phishing and credential security. Prioritizing the security of the "sazkafantasy.isport.blesk.cz" service, which appears frequently in targeted services, is also recommended.