In the coming age of information warfare, information security patterns take on a more offensive than defensive stance [1]. However, most existing security systems remain passive and do not provide an active form of security protection. It is necessary to develop an active form of offensive approach to security protection in order to guard vital information infrastructures and thwart hackers. This paper presents a Self-Extension Monitoring, a new approach in monitoring intruders, securing evidence against hackers and identifying them. It also proposes an Intruder Identification System (IIS), which is designed and implemented based on the proposed technique. The Self-Extension Monitoring approach minimizes temporal and spatial limitations, making it possible to collect enough information for disclosure of the intruder’s identity. A system security administrator can prevent any unwanted intrusion and re-attack the intruder by creating and maintaining information regarding the intruder...