Your attack surface is the sum of every attack vector that can be used to breach your perimeter defenses. In other words, it is the total quantity of information you are exposing to the outside world. Typically, the larger the attack surface, the more opportunities hackers will have to find a weak link which they can then exploit to breach your network. Professional hackers typically follow the cyber kill chain when attacking a target, and surveying the target's attack surface is normally the very first step in this process; what is known as advanced reconnaissance. Reducing the attack surface can minimize risk further down the cyber kill chain, preventing attacks before they even occur by eliminating potential attack vectors as early as possible. The cyber kill chain is a method of categorizing and tracking the various stages of a cyberattack from the early reconnaissance stages to the exfiltration of data.