Re: For Those Running Linux Servers . . .
mic-mac paddy whack, give a dog a bone, learn console and leave VNC alone.
I've really never played with any of the "hacking" canned tools because I find them to be ineffective, but, they are great starting points to look for vulnerabilities. A good "netstat -apvtu" should show what you have listening. A good ingress/egress firewall policy is a good idea.
I also like fail2ban.