SECURITY MONITORING DEVICE, COMMUNICATION SYSTEM, SECURITY MONITORING METHOD, AND COMPUTER READABLE MEDIUM

An electronic file copy notification reception unit acquires identification information on a terminal device connected to a first network switch to which a file server is connected, as first identification information, when the terminal device acquires a copy of an electronic file from the file server. A determination instruction unit acquires identification information on a device, as second identification information, when the device is newly connected to a second network switch different from the first network switch. The determination instruction unit matches the first identification information with the second identification information and instructs the second network switch to restrict communication to and from the terminal device via the second network switch in case where the first identification information coincides with the second identification information.