An apparatus controls transfer apparatuses that transfer a packet transmitted and received by terminals in a network. Upon receiving detection information notified from a server that detects unauthorized communication of a terminal by using the packet, the apparatus identifies the terminal and a type of the unauthorized communication, based on the detection information. The apparatus determines a transfer apparatus to be controlled, by referencing first information that stores information identifying the transfer apparatus in association with the terminal, and determines a control to be performed on the transfer apparatus by referencing second information that stores information on the control in association with the type of the unauthorized communication. The apparatus reads a control command corresponding to the control from third information that stores the control command in association with a type of the transfer apparatus, and transmits a control packet including the control command to the transfer apparatus.