Your wish is to change that ugly message which is always appearing when you log into a shell (eg: bash) on your Linux system?
Then: edit this file
and everything you put into it will appear just after logging in.
In order to disable login messages, simply make sure to add into /etc/ssh/sshd_config file the following line:
The login message can also be dynamically generated…and in fact that’s what actually happens in many systems (eg: my Ubuntu distro shows how many packages updates are available for downloading into the shell login message).
In order to create dynamic login messages, I suggest to:
prepare a shell script that echoes the desired content for the login message
disable motd file printing at login
launch your script at any login by adding the its command-line into the /etc/profile
script, which is a system-wide startup script