 This exploit functions with two purposes, as a port scanner and a mapper of trusted IP relationships between machines.The target system interacts with the ""zombie"" computer and difference in behaviour can be observed using different "zombies" with evidence of different privileges granted by the target to different computers.Discovered by Salvatore Sanfilippo (also known by his handle "Antirez") in 1998, the idle scan has been used by many black hat "hackers" to covertly identify open ports on a target computer in preparation for attacking it.