Disable Ctrl Alt Delete in Ubuntu

Disable Ctrl+Alt+Delete
First and foremost, anyone that has physical access to the keyboard can simply use the
Ctrl+Alt+Delete key combination to reboot the server without having to log on. Sure, someone could
simply unplug the power source, but you should still prevent the use of this key combination on a
production server.
This forces an attacker to take more drastic measures to reboot the server, and will
prevent accidental reboots at the same time.

• To disable the reboot action taken by pressing the Ctrl+Alt+Delete key combination, comment out
the following line in the file /etc/init/control-alt-delete.conf.

#exec shutdown -r now "Control-Alt-Delete pressed"

#sudo vi /etc/init/control-alt-delete.conf
# control-alt-delete - emergency keypress handling
#
# This task is run whenever the Control-Alt-Delete key combination is
# pressed, and performs a safe reboot of the machine.
description     "emergency keypress handling"
author          "Scott James Remnant <scott@netsplit.com>"
start on control-alt-delete
task
#exec shutdown -r now "Control-Alt-Delete pressed"