The AppSensor document is a conceptual framework that offers prescriptive guidance to implement intrusion detection capabilities into existing application utilizing standard security controls and recommendations for automated response policies based upon detected behaviour. When using AppSensor, an application will be able to identify malicious users within the application and eliminate the threat by taking response action such as logging out the user, locking the account or notifying an administrator.
An attacker often requires numerous probes and attack attempts in order to locate an exploitable vulnerability within the application. By using AppSensor it is possible to identify and eliminate the threat of an attacker before they are able to successfully identify an exploitable flaw.
For more information, please check out the project home page at OWASP AppSensor Project.