Set SSH Login Email Alerts In Linux Server

                        To enable server to automatically send a notification email to predefined email address every time someone logs in as root to the host. To configure the automatic email alert notification to a default email address on each incident of root logon on the server.

1. Update the Server : - apt-get update
2. Install Optional (apt-get install mailutils)
3. Install mailx client :- apt-get install bsd-mailx

                  During the installation Its ask for selecting following features “Postfix Configuration and Package Configuration” (Leave its as Default)

4. Login as root user and go to root’s home directory by typing cd /root command.

# cd /root

5. Open .bashrc file with vi or nano editor. Please remember .bashrc is a hidden file, you won’t see it by doing ls -l command. You’ve to use -a flag to see hidden files in Linux.

        root@ubuntu:~# ls -a

.  ..  .bash_history  .bashrc  .cache  .profile  .viminfo

root@ubuntu:~# vi .bashrc

                                              Add the following whole line at the bottom of the file. Make sure to replace “ServerName” with a hostname of your Server and change “your@yourdomain.com” with a your email address.

Syntax:- echo 'ALERT - Root Shell Access (ServerName) on:' `date` `who` | mail -s

"Alert: Root Access from `who | cut -d'(' -f2 | cut -d')' -f1`" your@yourdomain.com

Eg:- echo 'ALERT - SSH Access Detected To (ubuntu) on:' `date` `who` | mail -s "Alert: Root Access from `who | cut -d"(" -f2 | cut -d")" -f1`" ictops@gmail.com

6. Execute the following for instant result.

root@ubuntu:~# source .bashrc