Insider threats entail major security issues in geopolitics, cyber security and business organizations. Most earlier work in the field has focused on standard game theoretic approaches. We provide here two alternative, more realistic models based on adversarial risk analysis (ARA). ARA does not assume common knowledge and solves the problem from the point of view of just one of the players, the defender (typically), taking into account their knowledge and uncertainties regarding the choices available to them, to their adversaries, the possible outcomes, their payoffs/utilities and their opponents payoffs/utilities. The first model depicts the problem as a standard Defend-AttackDefend model. The second model segments the set of involved agents in three classes of users and considers both sequential as well as simultaneous actions. A data security example illustrates the discussion
