In this chapter, we looked at the concept of gaining access to a machine, and we also got an overview of ways to gain access. We also looked at the basics of server-side attacks, which are the techniques of gaining access to victims' machines. We saw how to use a default password or a misconfigured service to gain access to the target computer. We then saw how to use a service with a default password, a service that has not been configured correctly, and a service that came with a backdoor to gain full access to the target computer. We also looked at using Metasploit to connect to a backdoor that was installed on the FTP service. The next chapter will be about using the MSFC and Nexpose tools to scan and analyze vulnerabilities.