ModSecurity is a highly effective firewall for Apache web servers that's employed to prevent attacks against web applications. It keeps track of the HTTP traffic to a given site in real time and stops any intrusion attempts the instant it discovers them. The firewall relies on a set of rules to do that - as an example, attempting to log in to a script administration area unsuccessfully a few times triggers one rule, sending a request to execute a particular file which could result in getting access to the Internet site triggers another rule, and so forth. ModSecurity is amongst the best firewalls around and it'll secure even scripts which are not updated regularly because it can prevent attackers from employing known exploits and security holes. Quite comprehensive information about each intrusion attempt is recorded and the logs the firewall maintains are far more comprehensive than the standard logs provided by the Apache server, so you could later analyze them and decide whether you need to take additional measures in order to enhance the security of your script-driven Internet sites.