1. A method for risk assessment, comprising: evaluating historical authentication data to identify a set of authentication context properties associated with user authentication sessions; evaluating compromised user account data to identify a set of malicious account context properties associated with at least one of compromised user accounts or compromised user authentication events; annotating the set of authentication context properties and the set of malicious account context properties to create an annotated context properties training set; training a risk assessment machine learning module based upon the annotated context properties training set to generate a risk assessment model; identifying a current user account event of a current user; evaluating a current user context property of the current user using the risk assessment model to generate a risk analysis metric; and moderating the current user account event based upon the risk analysis metric.