An apparatus for mitigating a DDoS attack in a networked computing system includes at least one detector coupled with a corresponding router in the networked computing system. The detector is configured: to obtain network flow information from the router regarding current data traffic to at least one host; to compare the current data traffic to the host with stored traffic patterns associated with at least one prior DDoS attack; and to generate an output indicative of a match between the current data traffic and at least one of the stored traffic patterns. The apparatus further includes at least one mitigation unit coupled with the at least one detector. The mitigation unit is configured: to receive the output indicative of the match between the current data traffic and at least one of the stored traffic patterns; and to initiate a DDoS attack mitigation action in response to the received output.