Systems, methods, and apparatus, including computer programs encoded on computer storage media, for detecting insider fraud. One method includes identifying one or more insider threat detection rules for an enterprise and obtaining behavioral data for an enterprise insider from multiple behavioral data sources. The enterprise is associated with a plurality of enterprise insiders, and the behavioral data describes at least one action of the first enterprise insider. The method further includes determining a threat score for the first enterprise insider based on the behavioral data for the first enterprise insider and one or more of the insider threat detection rules and initiating, when the threat score satisfies a threat threshold, one or more protective actions.