Filter rule generation apparatus and filter rule generation method

A filter rule generation apparatus includes a storage unit and a processor. The storage unit is configured to store instructions. The processor, in accordance with each of the instructions stored on the storage unit, executes a process that causes the filter rule generation apparatus to perform extracting a co-occurrence message group per system, based on a co-occurrence probability, from a plurality of logs in which messages are accumulated, the messages being generated within systems, first generating value information representing a degree of similarity in operation between the systems, based on the extracted co-occurrence message group, clustering the systems, based on the value information, and second generating a rule for extracting messages from the logs of the systems included in each cluster, based on the co-occurrence message group in the cluster generated by the clustering.