Abstract: Network traffic can be prevented from entering a protected network. An alert can be received that can be triggered by network traffic that matches at least one signature that is associated with undesired network behavior. A source of the network traffic that triggered the alert can be determined, and network traffic that originates from the source can be blocked. Blocking the source can include assigning a determination to the alert. It can then be determined whether network traffic from the source should be blocked based on the determination. The source can then be provided to the protected network such that a network device coupled to the protected network can be configured to block network traffic that originates from the source.