Chapter 5. Tracking an Intruder on the Network

	"Beware the intentions of Uninvited Guests."
	--Samir Datt

Intruders on a network are any network administrators' worst nightmare. Survey after survey conducted by the world's most trusted organizations point indisputably to the fact that, statistically, when it comes to network breaches, it is not a matter of if my network gets breached, but a matter of when my network gets breached. Some of the famous sites and networks that have been attacked in the past include the Pentagon, NATO, White House, and so on. As a network forensics investigator, it is critical to understand ways and means of intrusion detection and prevention.

Intrusion detection/prevention systems come in a multitude of flavors. There can be a host-based IDS/IPS or network-based IDS/IPS. Host-based systems monitor activity on the host computer, whereas network-based systems monitor activity based on network traffic captures.

This chapter...