Prior to addressing the specific recipes mentioned in the list, we should address some of the underlying principles that will be discussed throughout the remainder of the chapter. Each of the recipes in this chapter will address tools that can be used to perform a few specific tasks. These tasks include banner grabbing, service identification, operating system identification, SNMP analysis, and firewall identification. Each of these tasks serves the common objective of gathering as much information about a target system as possible in order to be able to attack that system quickly and efficiently.
Before dedicating a large amount of time and resources to attempting to identify a remote service, we should determine whether that remote service will identify itself to us. Service banners consist of output text that is returned immediately when a connection is established with a remote service. It has historically...