Lynis - This is a popular security auditing tool that can be used to scan your system for vulnerabilities and provide recommendations for improving security. It is available in the Ubuntu repositories and can be installed using the following command:
sudo apt-get install lynis
chkrootkit - This is a tool that checks for known rootkits on your system. It can be installed using the following command:
sudo apt-get install chkrootkit
rkhunter - This is another tool that checks for rootkits, as well as other security issues such as hidden files and suspicious network activity. It can be installed using the following command:
sudo apt-get install rkhunter
Tiger - This is a security auditing tool that checks for a wide range of security issues, including file permissions, open ports, and system configuration settings. It can be installed using the following command:
sudo apt-get install tiger
These tools can be run from the command line and will provide detailed reports on any security issues they find. Keep in mind that no tool can guarantee complete security, but running these scripts regularly can help you identify and address common vulnerabilities.