|  |  | Another useful tool from L0pht is Antisniff. Sniffers are also used frequently and popularly by hackers to investigate information about networks and their data. Since sniffers are capable of looking at the data portion of a packet, they can identify passwords that are used to telnet to the routers. All of that information is passed in the clear, including the enable secret password and Cisco PIX passwords. Antisniff from L0pht Heavy Industries can alert a network administrator to a packet sniffer that is running on the network.