A method and system for discovering and testing security assets is provided. Based on source definition data describing sources to monitor on the one or more computer networks, an example system scans the sources to identify security assets. The system analyses the security assets to identify characteristics of the server-based applications. The system stores database records describing the security assets and the identified characteristics. The system queries the database records to select, based at least on the identified characteristics, one or more target assets, from the security assets, on which to conduct one or more security tests. Responsive to selecting the one or more target assets, the system conducts the one or more security tests on the one or more target assets. The system identifies one or more security vulnerabilities at the one or more target assets based on the conducted one or more security tests.