Installing UFW (Uncomplicated FireWall)

> sudo apt-get install ufw
> sudo ufw enable
> sudo ufw status
> sudo ufw logging on [this enables logging]
> sudo ufw allow ssh
> sudo ufw allow 80/tcp
> sudo ufw allow ftp
> sudo ufw allow smtp
> sudo ufw allow ftps
> sudo ufw allow proto tcp from any to any port 20000:20999 [this enabled the setting for ftps]
> sudo ufw delete allow ftps [this is to delete a rule]
> sudo ufw status [this is to view the firewall]
[now reboot your machine]

Using CHKROOTKIT

> apt-get install chkrootkit
> chkrootkit
[Ref: https://help.ubuntu.com/community/InstallingSecurityTools]

Secure Key generation: Admin User + Public key

[http://cloudservers.rackspacecloud.com/index.php/Ubuntu_-_Setup]
[Change the default shell to bash]
> sudo nano /etc/passwd
find your username and change from bin/sh to bin/bash
[this is load the default shell as bash]