Abstract: According to one embodiment of the invention, a system for preventing a network attack is provided. The system includes a computer having a processor and a computer-readable medium. The system also includes a shield program stored in the computer-readable medium. The shield program is operable, when executed by the processor, to transmit an agent to each of one or more nodes in a network in response to an attack directed to the network. The agent is operable to initiate a reduction of the effect of the attack on the node.