Footprinting (part of reconnaissance process) is the technique used for gathering information about a target system or network.For a hacker this kind of information is very useful to access or crack systems.The hackers might use various tools and techniques. Footprinting could be both passive and active. Footprinting is the first step to gather as much information as possible and find a way to intrude a target,this helps in deciding which type of attack is suitable for the target system.
Many information can be collected during this phase,information such as domain name,ip addresses,phone numbers,emails etc..,
Here are some of the tools used for footprinting sam spade,nslookup,traceroute,Nmap and neotrace.
Techniques used for Footprinting
Domain Name System(DNS)queries
Operating system identification
Simple Network Management Protocol(SNMP) queries
World Wide Web spidering
Uses of Footprinting
To gain information about a target system.
To use the information gained for targeting system in the future.