We present a method for an automatic discovery of cyberattacks in a distributed information system. The method creates a formal model of branching propagation of the attacker from the specification of software and hardware architecture enriched with multi-faceted access control information. The ensuing network of automata, decorated with unitary attack costs, enables a vast range of model checking techniques, in particular the search for the most efficient attack strategies. The model is expressive enough to cover a wide range of attack and defence approaches, like false data injection or redundant data sources.