Attack tree generation device, attack tree generation method, and computer readable medium

An attack tree generation method comprising:

• dividing a target system that is a target of a security countermeasure, into a plurality of sub-systems based on system configuration data indicating a configuration of the target system;
• selecting a sub-system in which a threat on security in the target system occurs, as a root system from among the plurality of sub-systems based on threat data indicating a content of the threat;
• executing an attack tree generation process on the root system, to thereby generate an attack tree of the root system, as a root tree;
• selecting one sub-system or more located on an intrusion course to the root system in the target system, as one descendent system or more from among the plurality of sub-systems based on intrusion course data indicating the intrusion course;
• executing the attack tree generation process on each of the one descendent system or more, to thereby generate one attack tree or more corresponding to the one descendent system or more, as one descendent tree or more;
• and
• integrating the root tree and the one descendent tree or more, to thereby generate an attack tree of the target system.

A non-transitory computer-readable medium storing an attack tree generation program which causes a computer to execute:

• a system dividing process of dividing a target system that is a target of a security countermeasure, into a plurality of sub-systems based on system configuration data indicating a configuration of the target system;
• a root system selection process of selecting a sub-system in which a threat on security in the target system occurs, as a root system from among the plurality of sub-systems based on threat data indicating a content of the threat;
• a root tree generation process of executing an attack tree generation process on the root system, to thereby generate an attack tree of the root system as a root tree;
• a descendant system selection process of selecting one sub-system or more located on an intrusion course to the root system in the target system, as one descendant system or more from among the plurality of sub-systems based on intrusion course data indicating the intrusion course;
• a descendant tree generation process of executing the attack tree generation process on each of the one descendent system or more, to thereby generate one attack tree or more corresponding to the one descendent system or more, as one descendent tree or more;
• and
• a sub-attack tree integration process of integrating the root tree and the one descendent tree or more, to thereby generate an attack tree of the target system.