The present disclosure is directed towards systems and methods for evaluating or mitigating a network attack. A device determines one or more client internet protocol addresses associated with the attack on the service. The device assigns a severity score to the attack based on a type of the attack. The device identifies a probability of a user account accessing the service during an attack window based on the type of attack. The device generates an impact score for the user account based on the severity score and the probability of the user account accessing the service during the attack window. The device selects a mitigation policy for the user account based on the impact score.