The present invention provides a policy specification framework to enable an enterprise to specify a given insider attack using a holistic view of a given data access, as well as the means to specify and implement one or more intrusion mitigation methods in response to the detection of such an attack. The policy specification provides for the use of "anomaly" and "signature" attributes that capture sophisticated behavioral characteristics of illegitimate data access. When the attack occurs, a previously-defined administrator (or system-defined) mitigation response (e.g., verification, disconnect, de-provision, network re-routing, or the like) is then implemented.