US Patent 7937761 Differential threat detection processing

Detecting a network security threat is disclosed. Network traffic is classified with a security risk related classification, the classification being determined at least in part by applying a threat detection heuristic to at least a portion of the network traffic. Classification data that indicates the security risk related classification into which the network traffic has been classified is added to the network traffic. The network traffic is subjected to a level of network security threat detection processing that corresponds to the security risk related classification into which the network traffic has been classified as determined based at least in part on the classification data.