A system for mitigating network attacks is provided. The system includes a protected network including a plurality of devices. The system further includes one or more attack mitigation devices communicatively coupled to the protected network. The attack mitigation devices are configured and operable to employ a recurrent neural network (RNN) to obtain probability information related to a request stream. The request stream may include a plurality of at least one of: HTTP, RTSP and/or DNS messages. The attack mitigation devices are further configured to analyze the obtained probability information to detect one or more atypical requests in the request stream. The attack mitigation services are also configured and operable to perform, in response to detecting one or more atypical requests, mitigation actions on the one or more atypical requests in order to block an attack.