DETERMINATION DEVICE, DETERMINATION SYSTEM, STORAGE MEDIUM STORING PROGRAM, AND DETERMINATION METHOD

A determination device includes a processor. The processor being configured to: send first information that is not conforming to a rule of a firewall to a control device, execute first determination processing in which the control device is determined to be in a malfunction state in a case in which a first notification acquired from the control device is a normal notification, and the control device is determined to be in a normal state in a case in which the first notification is an abnormal notification, additionally send second information conforming to the rule to the control device in a case in which the control device has been determined to be in a normal state, and execute second determination processing in which the control device is determined to be in a normal state in a case in which a second notification acquired from the control device is the normal notification.