System and method for assessing a risk level associated with launching acquired objects on an associated computer system. Events occurring on the computer system are detected, including an event representing launching of a first object. An association of a detected launching of the first object with user input effecting that launching, if any, is stored. In response to a launching of the first object, a determination is made as to whether an association exists between the launching, and any user input initiating that launching. A risk assessment record is updated for the first object such that, in response to the launching of the first object being either associated or not associated with user input initiating that launching, the risk assessment record is updated to reduce an indicated risk level for the first object, or to increase the indicated risk level for the first object, respectively.