AIDE (Advanced Intrusion Detection Environment) is a free
replacement for Tripwire(tm). It generates a database that can be
used to check the integrity of files on server. It uses regular
expressions for determining which files get added to the database.
You can use several message digest algorithms to ensure that the
files have not been tampered with.
Read more https://packetstormsecurity.com/files/172425/aide-0.18.3.tar.gz