Osiris is a Host Integrity Management System that periodically monitors
one or more hosts for change. It maintains detailed logs of changes to
the file system, user and group lists, resident kernel modules, and
more. Osiris can be configured to email these logs to the administrator.
Hosts are periodically scanned and, if desired, the records can be
maintained for forensic purposes. Osiris keeps an administrator apprised
of possible attacks and/or nasty little trojans. The purpose here is
to isolate changes that indicate a break-in or a compromised system.
Osiris makes use of OpenSSL for encryption and authentication in all
components.

WWW: http://osiris.shmoo.com/