I have a Managed VPS with Futurehosting. Early on when I first started with them some 2 years or more ago, I had them perform "server hardening".
Is security hardening a once and forget it or should the security hardening be performed periodically. Also, are there additional things recommended to be done to better harden a server?
From their website here is the items listed of what gets performed:
SIM - (System Integrity Monitor) - 24x7 Internal Monitoring of services.
SPRI - (System Priority) - Sets priority to current processes being run on your server, decreasing load 10-25%.
PRM - (Process Resource Monitor) - Monitors all resources used by all processes and if a process is being flooded or causing high load on the server, it is killed.
BFD - (Brute Force Detection) - Detects brute force connections and automatically enters the offending IPs into the firewall to be blocked.
CHKRootKIt – Simple script that detects software used by hackers. It scans once a day and emails the client if any suspicious scripts are found.
Firewall Installation - APF (Advanced Policy Firewall) iptables based firewall and anti-dos rulesets."
Yes, you have to upgrade the softwares to the latest version. For example chkrootkit 0.48 is now available, please make sure that latest version of it is running in the server.
Also If there are any third party scripts installed in the server,make sure that they are updated to the latest version.
If you're using the older versions, then there is a chance of getting it exploited.