File monitoring to pre-empt hacker We have a hacker occasionally attempting to hack a site, and so far unsuccessful, but I would like a way to determine if the site has been compromised (i.e., files edited). The type of attacks are LFI and attempting to inject iFrames in some source files. What can I install on my Debian server to alert me via an e-mail if certain files or directories are modified?

You can install Tripwire and introduce a set of dicrectory to Tripwire, When a file has been changed, Tripwire notifies sysadmin.