Install mod_spamhaus Apache module to fight comment spam
mod_spamhaus is an Apache module for DNS Block Listing that protects web services by denying access to particular IP addresses. It can stop spam relaying via web form URL injection, and block HTTP DDoS attacks from bot-nets.
It queries sbl-xbl.spamhaus.org, taking advantage of the Spamhaus Block List (SBL) and the Exploits Block List (XBL).
1. Install the package
apt-get install libapache2-mod-spamhaus
Disable root login to SSH
Allowing root logins to your SSH damon is a big security threat. If the SSH port is open, hackers will probably at some time attempt to brute force your root password. It's a good idea to disable root logins to SSH and instead use a normal user to login and use sudo to perform tasks that require root privileges.
1. Open the SSH daemon config file and change this line: (sudo pico /etc/ssh/sshd_config)
PermitRootLogin no
Add a sudoer (user allowed to use sudo)
Sudo allows a system administrator to delegate authority to give certain users (or groups of users) the ability to run some (or all) commands as root or another user while providing an audit trail of the commands and their arguments.
1. Create a new user (optional)
adduser user1