Hackers don't just show up, plug into the environment, and start hashing passwords to gain access into a server. There is a lot of time and effort they have to expel, for them just to get a foothold within the environment before they can get what they are ultimately looking for. To gain this foothold, often times, there are attacks on the infrastructure, which allow them to gain that entry point, establish that foothold, and move within the infrastructure from there.
The following sections will show some of the utilities and attacks on the wired infrastructure. Most of these can be prevented with the right configuration in place on the network-infrastructure side.