  Insider threats entail major security issues in geopolitics, cyber risk
management and business organization. The game theoretic models proposed so far
do not take into account some important factors such as the organisational
culture and whether the attacker was detected or not. They also fail to model
the defensive mechanisms already put in place by an organisation to mitigate an
insider attack. We propose two new models which incorporate these settings and
hence are more realistic. %Most earlier work in the field has focused on
%standard game theoretic approaches to find the solutions. We use the
adversarial risk analysis (ARA) approach to find the solution to our models.
ARA does not assume common knowledge and solves the problem from the point of
view of one of the players, taking into account their knowledge and
uncertainties regarding the choices available to them, to their adversaries,
the possible outcomes, their utilities and their opponents' utilities. Our
models and the ARA solutions are general and can be applied to most insider
threat scenarios. A data security example illustrates the discussion.
