A Taxonomy of Insider Threat in isolated (air-gapped) Computer Networks

Abstract

Mitigation of dangers posed by authorized and trusted insiders to the organization is a challenging Cyber Security issue. Despite state-of-the-art cyber security practices, malicious insiders present serious threat for the enterprises due to their wider access to organizational resources (Physical, Cyber) and good knowledge of internal processes with potential vulnerabilities. The issue becomes particularly important for isolated (air-gapped) computer networks, normally used by security sensitive organizations such as government, research and development, critical infrastructure (e.g. power, nuclear), finance, and military. Such facilities are difficult to compromise from outside; however, are quite much prone to insider threats. Although many insider threat taxonomies exist for generic computer networks; yet, the existing taxonomies do not effectively address the issue of Insider Threat in isolated computer networks. Thereby, we have developed an insider threat taxonomy specific to isolated computer networks focusing on actions performed by the trusted individual(s), Our methodology is to identify limitations in existing taxonomies and map real world insider threat cases on proposed taxonomy. We argue that for successful attack in an isolated computer network, the attack must manifest in both Physical and Cyber world. The proposed taxonomy systematically classifies different aspects of the problem into separate dimensions and branches out these dimensions into further sub-categories without loss of general applicability. Our multi-dimensional hierarchical taxonomy provides comprehensive treatment of the insider threat problem in isolated computer networks; thus, improving situational awareness of the security analyst and helps in determining proper countermeasures against perceived threats. Although many insider threat taxonomies exist for generic computer networks; yet, the existing taxonomies do not effectively address the issue of Insider Threat in isolated computer networks. Thereby, we have developed an insider threat taxonomy specific to isolated computer networks focusing on actions performed by the trusted individual(s), Our methodology is to identify limitations in existing taxonomies and map real world insider threat cases on proposed taxonomy. We argue that for successful attack in an isolated computer network, the attack must manifest in both Physical and Cyber world. The proposed taxonomy systematically classifies different aspects of the problem into separate dimensions and branches out these dimensions into further sub-categories without loss of general applicability. Our multi-dimensional hierarchical taxonomy provides comprehensive treatment of the insider threat problem in isolated computer networks; thus, improving situational awareness of the security analyst and helps in determining proper countermeasures against perceived threats. The proposed taxonomy systematically classifies different aspects of the problem into separate dimensions and branches out these dimensions into further sub-categories without loss of general applicability. Our multi-dimensional hierarchical taxonomy provides comprehensive treatment of the insider threat problem in isolated computer networks; thus, improving situational awareness of the security analyst and helps in determining proper countermeasures against perceived threats.