Abstract: Various embodiments of the present disclosure are directed to methods for checking the security of a technical unit, wherein at least one first plausible model variant is determined. In one example embodiment, the method includes the following steps carried out on a test computer system: assigning known vulnerabilities to components of the model variants; defining an attack aim; creating at least one attack model, based on the attack aim, for each model variant; weighting the nodes of the attack model with respect to at least one evaluation variable; determining an evaluation of at least one test vector of the attack model with respect to the evaluation variable; determining a security value as the pessimal value of all evaluations; and issuing a security confirmation if the security value corresponds to a security criterion.