Samhain is a tool for verifying the integrity of files. It uses the TIGER message digest algorithm to generate a database for files and directories listed in the configuration file. After initializing the database, samhain can run as a background process, performing checks at user-defined intervals. Results can be written to a log file and/or forwarded to another host by e-mail. Log file entries are signed to prevent tampering. The current version is tested on Linux only.
You can download it from the following link: https://packetstormsecurity.com/files/download/11455/samhain-0.4.tar.gz
Source: https://packetstormsecurity.com/files/11455/Samhain-File-Integrity-Checker.html