ModSecurity is a powerful web app layer firewall for Apache web servers. It monitors the whole HTTP traffic to a site without affecting its performance and when it identifies an intrusion attempt, it prevents it. The firewall additionally maintains a more comprehensive log for the website visitors than any server does, so you'll manage to monitor what is going on with your sites much better than if you rely simply on standard logs. ModSecurity uses security rules based on which it stops attacks. For instance, it identifies whether someone is trying to log in to the administrator area of a particular script several times or if a request is sent to execute a file with a certain command. In these cases these attempts set off the corresponding rules and the firewall program blocks the attempts instantly, after that records comprehensive info about them within its logs. ModSecurity is amongst the best software firewalls out there and it can protect your web apps against a large number of threats and vulnerabilities, particularly if you don’t update them or their plugins regularly.