Choosing a Security Model Based on Your Security Risks

The Internet today is not an especially friendly place for servers, and as an administrator you must always fear and prepare for the worst. The proliferation of "rootkit" toolsprepackaged weapons that attackers can use to gain superuser access to your systemand published attack scripts provides unfortunate fodder for countless individuals with nothing better to do than pursue destructive hobbies. You must assume that your system is being probed for security weaknesses at all times and expect the situation to grow more dangerous with each new published exploit. Your only defense is to keep your system as up to date as possible, act on new security advisories as soon as they're released, run only what services are necessary, and be educated about the real dangers that threaten your system and where the greatest risks lie.