A fraud detection system, comprising at least one processor configured to: acquire, based on a first fraud detection engine for detecting a fraud in a first service, a second fraud detection engine for detecting a fraud in a second service; acquire fraud information relating to a fraud that has actually occurred in the second service; determine, based on the fraud information, whether a fraud in the second service is detectable by the second fraud detection engine; and apply, when it is determined that a fraud in the second service is detectable by the second fraud detection engine, the second fraud detection engine to the second service.