Computing the impact of cyber attacks on complex missions

This paper describes how to evaluate the impact of a cyber attack on a mission. We accomplish this by computing impact as the changes to mission measures of effectiveness, based on the reported effects of a known or suspected attack on one or more parts of the information technology (IT) supporting the mission. Our previous papers have described our goals for computing mission impact and the choices of the techniques we use for modeling missions, IT, and cyber attacks. This paper focuses on how we compute the impact of cyber attacks on IT processes and information. These computations will improve decision-making when under cyber attack by providing accurate and detailed assessments of the impact of those attacks. Although the focus of our work has been on the calculation of cyber mission impacts during mission execution, we have also demonstrated how our representations and computations can be used for performing cyber risk analysis and crown jewels analysis.