Client computers track visited websites and monitor confidential information transmitted to the visited websites. Upon subsequent identification of a website as malicious or compromised, it is determined whether the unsecure website was visited, and if so, whether any confidential information was exposed to the unsecure website. Clients compile statistical reports concerning confidential information transmitted to unsecure websites, and provide these reports to a central server. The central server uses statistical reports received from a wide distribution of clients to maintain comprehensive statistical data indicating exposure of confidential information to unsecure websites. This comprehensive statistical data can be used for purposes such as damage assessment, trend tracking and profiling of suspected malicious websites.