13. A computer implemented method for risk assessment, comprising: a computer system evaluating historical authentication data to identify a set of authentication context properties associated with user authentication sessions; a computer system 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; a computer system annotating the set of authentication context properties and the set of malicious account context properties to create an annotated context properties training set; a computer system training a plurality of risk assessment machine learning modules based upon the annotated context properties training set to generate a plurality of risk assessment models, wherein each risk assessment model is responsive to a predefined context property; a computer system identifying a current user account event of a current user; a computer system evaluating a first current user context property of the current user using a first risk assessment model; a computer system evaluating a second current user context property of the current user using a second risk assessment model; a computer system aggregating results from the first and the second risk assessment models to generate a risk analysis metric; and a computer system moderating the current user account event based upon the risk analysis metric, wherein the current user account event is moderated by the computing system blocking the current user for a current session of the current user account event.
13. A computer implemented method for risk assessment, comprising: a computer system evaluating historical authentication data to identify a set of authentication context properties associated with user authentication sessions; a computer system 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; a computer system annotating the set of authentication context properties and the set of malicious account context properties to create an annotated context properties training set; a computer system training a plurality of risk assessment machine learning modules based upon the annotated context properties training set to generate a plurality of risk assessment models, wherein each risk assessment model is responsive to a predefined context property; a computer system identifying a current user account event of a current user; a computer system evaluating a first current user context property of the current user using a first risk assessment model; a computer system evaluating a second current user context property of the current user using a second risk assessment model; a computer system aggregating results from the first and the second risk assessment models to generate a risk analysis metric; and a computer system moderating the current user account event based upon the risk analysis metric, wherein the current user account event is moderated by the computing system blocking the current user for a current session of the current user account event. 19. The method of claim 13 , wherein the method further includes retroactively banning the current user account based upon the evaluation metric.