Download Lynis: https://packages.cisofy.com
Install Lynis on Ubuntu 16.04.4 LTS
sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys C80E383C3DE9F082E01391A0366C67DE91CA5D5F
sudo apt install apt-transport-https
echo 'Acquire::Languages "none";' | sudo tee /etc/apt/apt.conf.d/99disable-translations
echo "deb https://packages.cisofy.com/community/lynis/deb/ xenial main" | sudo tee /etc/apt/sources.list.d/cisofy-lynis.list
sudo apt update
sudo apt install lynis
lynis --version
sudo lynis audit system
lynis show details
sudo less /var/log/lynis.log