An information security apparatus includes a plurality of monitoring modules that monitor for tampering. A management apparatus includes a reception unit that receives a plurality of monitoring results each generated by a source monitoring module monitoring a target monitoring module; a detection unit that detects an abnormality by referring to fewer than all of the received monitoring results; and an identification unit that identifies, when an abnormality is detected, a monitoring module that has been tampered with from among (i) a monitoring module that generates a monitoring result related to the abnormality, and (ii) one or more monitoring modules identified by tracing back through a chain of monitoring modules consecutively from the target of monitoring to the source of monitoring, starting from the monitoring module that generates the monitoring result related to the abnormality.