Lynis is an open source security auditing tool which is widely used on various Unix-like operating systems. With Lynis, system administrators and security professionals can perform in-depth system-wide security scans in a matter of minutes.
In this article, I will explain how to install and use Lynis on a CentOS 7 server.
Log in from an SSH terminal as a sudo user, and then update the system as follows:
sudo yum install epel-release -y sudo yum update -y sudo shutdown -r now
After the system reboot, log in back as the same sudo user.
On CentOS 7, you can easily install Lynis using the EPEL YUM repo which has been installed earlier:
sudo yum install lynis -y
If you want to enhance Lynis' functionality, you can install Lynis plugins (community) which can only be obtained from subscription:
Now, download and unzip the plugins archive as follows:
cd wget http://sable.madmimi.com/c/6938?id=44150.2674.1.a12c46882ca668ab69e63acbe670c747 -O lynis-community-plugins.tar.gz sudo tar -zxvf lynis-community-plugins.tar.gz --strip-components=1 -C /usr/share/lynis/plugins
Setup proper permissions:
sudo chown root:root /usr/share/lynis/plugins/plugin_* sudo chmod 600 /usr/share/lynis/plugins/plugin_*
Finally, check the Lynis profile file to make sure that newly-added plugins (which are
systemd in our case) are enabled:
sudo grep plugin= /etc/lynis/default.prf
The output should include
plugin=compliance plugin=configuration plugin=control-panels plugin=crypto plugin=dns plugin=docker plugin=file-integrity plugin=file-systems plugin=firewalls plugin=forensics plugin=intrusion-detection plugin=intrusion-prevention plugin=kernel plugin=malware plugin=memory plugin=nginx plugin=pam plugin=processes plugin=security-modules plugin=software plugin=system-integrity plugin=systemd plugin=users
Simply running Lynis without any parameter will display the Lynis parameters:
If you want to perform a full security scan, use the following command:
sudo lynis audit system
All scan results will be stored in the Lynis log file
After the full security scan, you can sort out all
Warning messages from the Lynis log file using the below grep command:
sudo grep Warning /var/log/lynis.log
Similarly, you can display all
Suggestion messages using another grep command:
sudo grep Suggestion /var/log/lynis.log
That's it. If you want to learn more details about Lynis, please visit Lynis official website.