In methods and a device for mitigating against cyber-attack on a network, a distributed intermediary device is placed into a network between computers or network nodes of the network to mitigate cyber-attacks between the computers or nodes of a network from remote systems. Threats are assessed by utilizing internal information assurance mechanisms of the device to detect such cyber-attacks without requiring external modification of the software and/or hardware of the computers or nodes of the network to be protected. The device prevents attacks at the platform level against the OS and network resources.