Analysis apparatus, analysis system, analysis method, and non-transitory computer readable medium storing program

An analysis system comprising a plurality of analysis apparatuses, wherein

• each of the analysis apparatuses comprises:
• hardware, including a processor and memory;
• an analysis target selection unit implemented at least by the hardware and configured to select entities to be analyzed from among entities which are elements of an information processing system;
• an attack graph generation unit implemented at least by the hardware and configured to generate an attack graph for a set of the selected entities;
• and
• a countermeasure implementation assumption unit implemented at least by the hardware and configured to assume that a countermeasure for invalidating an attack condition is implemented in the generated attack graph,
• in each of the analysis apparatuses, a series of processes including a process of the analysis target selection unit, a process of the attack graph generation unit, and a process of the countermeasure implementation assumption unit is repeated over a plurality of cycles until all the entities of the information processing system to be analyzed have been selected as analysis targets,
• the attack graph generation unit generates the attack graph on a precondition that the countermeasure for invalidating the attack condition assumed by the countermeasure implementation assumption unit has been implemented,
• the analysis target selection unit selects at least an entity that becomes a starting point of an attack and an entity that becomes a final target of the attack in a first cycle of the plurality of cycles and gradually adds remaining entities to the analysis targets in subsequent cycles until all the entities to be analyzed have been selected as the analysis targets,
• the analysis target selection unit of each of the analysis apparatuses selects subsets of entities different from each other, the subsets belonging to a set composed of all the entities to be analyzed, and
• one of the analysis apparatuses summarizes processing results of the countermeasure implementation assumption units of all the analysis apparatuses, and generates an attack graph for the set of all the entities to be analyzed based on the processing results.

An analysis method comprising:

• performing a process for selecting entities to be analyzed among entities which are elements of an information processing system;
• performing a process for generating an attack graph for a set of the selected entities;
• and
• performing a process for assuming implementation of a countermeasure for invalidating an attack condition in the generated attack graph, wherein
• a series of processes including the process for selecting entities to be analyzed, the process for generating an attack graph, and the process for assuming implementation of a countermeasure is repeated over a plurality of cycles until all the entities of the information processing system to be analyzed have been selected as analysis targets,
• in the process for generating an attack graph, the attack graph is generated on a precondition that the countermeasure for invalidating the attack condition assumed in the process for assuming implementation of a countermeasure has been implemented, and
• in the process for selecting entities to be analyzed, at least an entity that becomes a starting point of an attack and an entity that becomes a final target of the attack are selected in a first cycle of the plurality of cycles, and remaining entities are gradually added to the analysis targets in subsequent cycles until all the entities to be analyzed are selected as the analysis targets.

A non-transitory computer readable medium storing a program for causing a computer to perform:

• an analysis target selection step of selecting entities to be analyzed among entities which are elements of an information processing system;
• an attack graph generation step of generating an attack graph for a set of the selected entities;
• and
• a countermeasure implementation assumption step of assuming implementation of a countermeasure for invalidating an attack condition in the generated attack graph, wherein
• a series of processes including a process of the analysis target selection step, a process of the attack graph generation step, and a process of the countermeasure implementation assumption step is repeated over a plurality of cycles until all the entities of the information processing system to be analyzed have been selected as analysis targets,
• in the attack graph generation step, the attack graph is generated on a precondition that the countermeasure for invalidating the attack condition assumed in the countermeasure implementation assumption step has been implemented, and
• in the analysis target selection step, at least an entity that becomes a starting point of an attack and an entity that becomes a final target of the attack are selected in a first cycle of the plurality of cycles, and remaining entities are gradually added to the analysis targets in subsequent cycles until all the entities to be analyzed are selected as the analysis targets.