I. Introduction
Insider threat is a breach in the security of target organisation. As per study, organisations have to tackle with the different types of threats which may cause in security breach. Insider threat is difficult to detect and to deal with as it is caused by insiders who are authorised persons of the organizations with all the access to the confidential information and resources. The insiders may be malicious, preparators, but the most commonly found insiders are malicious which attempts the threats intentionally [1] [2]. Many cybercrimes were found as caused by malicious insiders. Some of the techniques used for detection has analyzed user's behavior by considering audit data i.e. the data that is host based which actually record the activities of users done on computer, data based on network which is recorded by equipment connected to network and context data which records the information of the user's profile. According to recent research the insider threat detection can be categorized in 7 different classes that are classified based on strategies and features- (i) Role based access (ii) Anomaly based (iii) Scenario based (iv) psychological risk factors (v) honey pot (vi) network based (vii) graph based. However existing techniques endure good insider threat detection but the traditional machine learning methods are not able to use user behavior data in full for detection and only anomalous behavior[3] [4].