A network router includes a set of interface cards to receive packets from a network, and a set of accounting modules to calculate flow statistics for the packets. The router further includes a control unit to adaptively update routing information in response to the calculated flow statistics, and to route the packets in accordance with the routing information. The control unit identifies potentially malicious packet flows for the received packets based on the flow statistics, and applies an intercept filter to intercept the packets of the identified packet flows. The control unit analyzes the intercepted packets in real-time to determine the presence of a network event, and updates the routing information based on the determination, e.g., by terminating routing for packets associated with malicious packet flows. In this manner, the router may adaptively respond to network events, such as network security violations.