How do I prevented the hackers (secret intel) manipulating my terminal again
Most likely you have sprung to an incorrect conclusion - that your Mac was hacked.

The most likely cause of "unwanted" or "surprising" host name changes is that your DHCP server gave your computer a new hostname. The DHCP server could be a router/modem in your own house, a system at your ISP or indeed hardware at anywhere you have connected to a WiFi network (such as a coffee shop, school or whatever).

Removing sudo rights from yours won't help this problem, as the DHCP client on your Mac will still be able to change your hostname.