Writing Metasploit Exploits. Part 4 of a series of tutorials.
You can download it from the following link: https://packetstormsecurity.com/files/download/82743/exploit-writing-tutorials-part-4-from-exploit-to-metasploit-the-basics.pdf
Source: https://packetstormsecurity.com/files/82743/Writing-Metasploit-Exploits.html