Mod_security(ModSecurity is an open source intrusion detection and prevention engine for web applications)
Features
• filtering POST and GET requests (including hearders)
• filters inheritance and ability to add filters in each vhosts configuration file, and per directory
• include a way to chroot apache in an easiest way
• ability to fake apache output (like telling “Microsoft IIS” on error page or whatever you want to display)
• can store uploaded files in a tmp directory and call an anti-virus scan like clamav on these files
