VisualSniffer is a powerful packet capture tool and network intrusion detection system for Windows system. It can perform protocol analysis, content searching/matching based on user defined rules in real-time and notify users by e-mail, sound, and text message when intrusion is detected. VisualSniffer provides hundreds of built-in rules for detecting a variety of attacks and probes, such as buffer overflows, port scans, CGI attacks, OS fingerprinting attempts? VisualSniffer provides graphical and statistical displays with colored charts and decodes TCP, UDP, and ICMP packets down to the lowest layer. IP packets are organized based on their source and destination addresses and TCP/IP packets are further grouped into connections. The users can also define workspaces to view special groups of packets.