This book is an introduction to initial access methods in offensive cybersecurity with a focus on Metasploit. Metasploit is an open source penetration testing framework that allows users to combine and use modules. These modules can be exploits, which are used to gain access to targets; they can be payloads, which form code that is run on targets; they can be auxiliary support modules like scanners and reconnaissance tools. Metasploit is an excellent entry-level offensive tool with mature documentation. Security professionals across the world make use of Metasploit.