ModSecurity is an efficient firewall for Apache web servers which is used to stop attacks against web applications. It monitors the HTTP traffic to a particular website in real time and blocks any intrusion attempts the moment it discovers them. The firewall relies on a set of rules to accomplish that - for example, attempting to log in to a script admin area unsuccessfully a few times activates one rule, sending a request to execute a certain file which may result in accessing the Internet site triggers another rule, and so on. ModSecurity is among the best firewalls out there and it will preserve even scripts which aren't updated regularly as it can prevent attackers from employing known exploits and security holes. Very thorough information about every single intrusion attempt is recorded and the logs the firewall keeps are a lot more specific than the standard logs provided by the Apache server, so you could later take a look at them and decide whether you need to take additional measures in order to boost the safety of your script-driven websites.