Application Audit Trail Analysis

Abstract

An application audit trail may be analyzed for a number of reasons; performance enhancement of networks and computers, identification of security incidents and operational problems as well as fraud tracking. In this thesis, focus lies on detecting intrusions into information systems. An approach for analysis of an audit trail from an arbitrary application is presented. It's extensible and allows for further methods of analysis to be incorporated. For the purpose of this thesis, two methods were implemented and used in parallel to find intrusions. A technique for labeling signaled intrusions with an indication of their certainty is developed. This allows for focus on alarms with a higher certainty, and will thus facilitate a faster response. The analysis system was tested against several scenarios. All which contained intrusions were detected. Among these, all but one was deemed as an intrusion with highest certainty. Further, the amount of false positives when analyzing the test datasets were only fraction of a percentage.