A method includes first determining whether a character string related to a specific type, from among types of a plurality of files, is included in attribute information of each of the plurality of files which a process that is being executed refers to or updates, second determining the types of each of the plurality of files using higher priority which is given to a first file than a second file from among the plurality of files, the first file having a first attribute information which includes the character string, the second file having a second attribute information which does not include the character string, and outputting a determination result regarding the types related to the plurality of files.