NIS in Directory Utility

Hi,

On my Macbook Pro running Yosemite, I have three items under "Name" in my directory utility:

Active Directory

LDAPv3

NIS

On my mac pro running High Sierra, I only have "/Local/Default", so this makes me concerned. Also, in my macbook pro, I've had many issues including the Guest user being active but showing as not active in the user preferences. The guest user had "enable parental controls" checked and a profile created, but the "allow guests to log into this computer" was not checked. Yet it was showing up upon logging out.

According to Apple, I've been legitimately hacked before, when the root user was enabled and showing a "other" profile upon logging out. This was likely done by someone I knew who had been arrested for ID Fraud and said he could remotely hack any device using kali linux. I understand I may be reading into things. But my macbook pro is extremely slow, and at one point I couldn't remove the wifi from my network preferences (it kept crashing the app when I tried).

Other things that have concerned me have been kernal_task taking up 180% of CPU, my fan running high upon startup, "bash-3.2" showing on single user mode instead of my name, and upon typing exit in single user mode I get a bunch of processes running.

Any ideas on what any of this means, if anything, I'd appreciate it.