A system, method, and device are presented for assessing a target network's vulnerability to a real cyberthreat based on determining policy-based synthetic tests configured to model the behavior of the cyberthreat. Real-time feedback from the target network (e.g., servers, desktops, and network/monitoring hardware and/or software equipment) are received, analyzed, and used to determine whether any modifications to the same or a new synthesized test is preferred. The technology includes self-healing processes that, using the feedback mechanisms, can attempt to find patches for known vulnerabilities, test for unknown vulnerabilities, and configure the target network's resources in accordance with predefined service-level agreements.