Provided is a tampering monitoring system that can identify a monitoring module that has been tampered with among a plurality of monitoring modules. A management apparatus is provided with an acquisition unit that acquires a new monitoring module that has not been tampered with, a generation unit that generates a decoy monitoring module by modifying the acquired monitoring module, a transmission unit that transmits the decoy monitoring module to the information security device and causes the information security device to install the decoy monitoring module therein, a reception unit that receives from the information security device, after the decoy monitoring module has been installed, monitoring results generated by the monitoring modules monitoring other monitoring modules, and a determination unit that identifies, by referring to the received monitoring results, a monitoring module that determines the decoy monitoring module to be valid and determines the identified monitoring module to be invalid.