Packet sniffing is a technique of monitoring every packet that crosses
the network. A packet sniffer is a piece of software or hardware that
monitors all network traffic. The security threat presented by sniffers
is their ability to capture all incoming and outgoing traffic, including
clear-text passwords and usernames or other sensitive material. While
packet sniffers can be fully passive, some aren't, therefore they can be
detected. This paper discusses the different methods that AntiSniff uses
to detect these sniffing programs.