ABNORMAL VEHICLE DETECTION SERVER AND ABNORMAL VEHICLE DETECTION METHOD

An anomalous vehicle detection server (10) includes an anomaly score calculator (106) that detects a suspicious behavior different from a predetermined driving behavior based on pieces of vehicle information that are received from a plurality of vehicles, respectively, and are each based on a vehicle log including the content of an event that has occurred in a vehicle system (20) provided in the vehicle, and acquires an anomaly score of each of the plurality of vehicles that indicates a likelihood that reverse engineering is performed on the vehicle; and an anomalous vehicle determiner (108) that determines whether one vehicle of the plurality of vehicles is an anomalous vehicle based on the anomaly score of the one vehicle and a statistical value of the anomaly scores of two or more vehicles of the plurality of vehicles.