The present disclosure provides a security assessment apparatus, a method, and a program capable of making an assessment of a security risk simply and appropriately. The security assessment apparatus according to the present disclosure is a security assessment apparatus of a facility to be controlled using a controller, including: an identification unit (15) configured to identify a compromised component which puts the facility into an unsafe situation based on data regarding a plurality of components provided in the facility and control program code of the controller, thereby generating a list of the compromised component; and a compromised behavior generating unit (16) configured to generate a compromised behavior of a selected component selected from the list of the compromised component.