A computer implemented method to detect a data breach in a network-connected computing system, the method including storing, at a trusted secure computing device, at least a portion of network traffic communicated with the computer system; the computing device generating a copy of data distributed across a network; the computing device identifying information about the network attack stored in the copy of the data; the computing device generating a signature for the network attack based on the information about the network attack, the signature including rules for identifying the network attack in network traffic; and identifying an occurrence of the network attack in the stored network traffic based on the signature.