FCheck is a very stable perl script written to generate and comparatively monitor a UNIX system against its baseline for any file alterations and report them through syslog, console, or any log monitoring interface. Monitoring events can be done very frequently if a system’s drive space is small enough, making it more difficult to circumvent. This is a freely-available open-source alternative to ‘tripwire’ that is time tested, and is easier to configure and use.
You can download it from the following link: https://packetstormsecurity.com/files/download/23599/FCheck_2.07.54.tar.gz
Source: https://packetstormsecurity.com/files/23599/FCheck_2.07.54.tar.gz.html