In this chapter, we will be writing our first footprinting and fingerprinting intelligence discovery tools in Perl. As mentioned in the previous chapters, a few tools come with default installations of Linux, and a lot of others are easily accessible via the distribution's precompiled package management repositories. We will analyze the traffic with Wireshark and mimic the behavior of a few of these tools using only Perl and Perl modules from CPAN. If you haven't used CPAN modules before, it's best to look back at Chapter 1, Perl Programming, to learn how they are installed.
In this chapter, we will be covering the following topics: