A system and method are provided for detecting extension attacks made to a communication enterprise, and taking appropriate remedial action to prevent ongoing attacks and future attacks. One or more attributes of a suspect call are analyzed, and a risk is associated with each analyzed attribute. An overall risk or assessment is then made of the analyzed attributes, attack attributes are logged, and one or more remedial actions may be triggered as a result of the analyzed call attributes. The remedial actions may include recording the call, notifying an administrator of a suspect call, or isolating the communication enterprise from the attack by terminating the call or shutting down selected communication endpoints to prevent calls being made to those extensions. Rules may be applied to the analyzed attributes in order to trigger the appropriate remedial action. The call attributes analyzed may include call destination, call direction, call type, time of day of the call, call duration, whether a call source is spoofed, call volume from a particular call source, and hash values created for a suspect media stream.