Patent ID: 7152105

Claim:
A system for determining an operating system of a target computer operably connected to a network, the system comprising: first and second data packets, said first and second data packets compliant with a protocol supported by said network, said first and second data packets transmitted via said network to said target computer; first and second operating system fingerprints comprising data bits stored in a computer-readable medium, said first and second operating system fingerprints associated with a first operating system; a first target computer fingerprint comprising data bits stored in a computer-readable medium, said first target computer fingerprint including a representation of at least a portion of data received in response to said transmission of said first data packet; a second target computer fingerprint comprising data bits stored in a computer-readable medium, said second target computer fingerprint including a representation of at least a portion of data received in response to said transmission of said second data packet; and fingerprint comparison instructions embodied in a computer readable storage medium, said instructions executable by a computer to compare said first operating system fingerprint and said first target computer fingerprint, to compare said second operating system fingerprint and said second target computer fingerprint, and to generate a result indicative of whether said first operating system was running on said target computer; wherein the first and second data packets each include TCP packets.