1. A method comprising: receiving, by an electronic front-end unit, communication traffic of a computer system from one or more sources; identifying, by an electronic correlation unit, in the received communication traffic a cyber security event and a physical security event, wherein the cyber security event is an occurrence of unauthorized access to the computer system through the use of malicious software, and wherein the physical security event is an occurrence of unauthorized physical entry into a location where the computer system is physically located; and identifying, by the electronic correlation unit, an intrusion by correlating the cyber security event and the physical security event by using location-based correlation and identity-based correlation.