CYBER THREAT DEFENSE SYSTEM PROTECTING EMAIL NETWORKS WITH MACHINE LEARNING MODELS

A cyber defense system using models that are trained on a normal behavior of email activity and user activity associated with an email system. A cyber-threat module may reference the models that are trained on the normal behavior of email activity and user activity. A determination is made of a threat risk parameter that factors in the likelihood that a chain of one or more unusual behaviors of the email activity and user activity under analysis fall outside of a derived normal benign behavior. An autonomous response module can be used, rather than a human taking an action, to cause one or more autonomous rapid actions to be taken to contain the cyber-threat when the threat risk parameter from the cyber-threat module is equal to or above an actionable threshold.