Modeling the Stuxnet attack with BDMP: Towards more formal risk assessments

Attack modeling has recently been adopted by security analysts as a useful tool in risk assessment of cyber-physical systems. We propose in this paper to model the Stuxnet attack with BDMP (Boolean logic Driven Markov Processes) formalism and to show the advantages of such modeling. After a description of the architecture targeted by Stuxnet, we explain the steps of the attack and model them formally with a BDMP. Based on estimated values of the success probabilities and rates of the elementary attack steps, we give a quantification of the main possible sequences leading to the physical destruction of the targeted industrial facility. This example completes a series of papers on BDMP applied to security by modeling a real case study. It highlights the advantages of BDMP compared to attack trees often used in security assessment.