Display a legal warning before login(SSH).

Create a file called /etc/ssh/sshd-banner.

Paste the customized banner message in it.
For example:
"This Machine is for the exclusive use of XYZ organization and Unauthorized access or breach of these terms may result in termination of your authorization and/or criminal penalties."

edit /etc/ssh/sshd_config with following entry

Banner /etc/ssh/sshd-banner


Restart sshd service using.

#service sshd restart

To validate the changes:
Try to login to the server using putty.
put username and press enter .
You should get banner displaying text under /etc/ssh/sshd-banner file.

For example:

login as: root
"This Machine is for the exclusive use of XYZ organization and Unauthorized access or breach of these terms may result in termination of your authorization and/or criminal penalties."
root@'s password:


Click here for more reference:
http://www.cyberciti.biz/tips/change-openssh-sshd-server-login-banner.html