An attack impact prediction system for providing network security for computer networks is disclosed. A computer network includes multiple attack impact prediction (AIP) agents. In response to a detection of an intrusion to a computer network, an AIP agent is notified of the intrusion. In turn, the AIP agent broadcasts the detected intrusion to other AIP agents within the computer network. An impact of the detected intrusion is then determined at each node by its respective AIP agent. In response to a determination that an impact of the detected intrusion on a node exceeds a predetermined severity threshold, then actions need to be taken by each respective AIP agent is ascertained. Finally, the ascertained actions are performed by one or more AIP agents at various points within the computer network.