https://github.com/imthenachoman/How-To-Secure-A-Linux-Server
https://github.com/decalage2/awesome-security-hardening
https://www.pluralsight.com/blog/it-ops/linux-hardening-secure-server-checklist
https://www.cyberciti.biz/tips/linux-security.html
https://ubuntu.com/blog/what-is-system-hardening-definition-and-best-practices
https://ivansalloum.com/linux-server-security-and-hardening/
https://github.com/CISOfy/Lynis