Systems and methods are disclosed for identifying resources responsible for events. In one embodiment, a method may include determining a number of unique actors in a plurality of actors that have accessed the resource. The method may further include identifying from the plurality of actors a set of affected actors that has been affected by an event and identifying from the set of affected actors a subset of resource-affected actors that accessed the resource prior to being affected by the event. The method may further include determining a number of resource-affected actors in the subset of resource-affected actors and, based on the number of unique actors and the number of resource-affected actors, determining an event score for the resource. The event score may be a lower bound of a confidence interval of a binomial proportion of the number of resource-affected actors to the number of unique actors.