The samhain open source host-based intrusion detection system (HIDS) provides 
file integrity checking and logfile monitoring/analysis, as well as rootkit 
detection, port monitoring, detection of rogue SUID executables, and hidden 
processes. 

It has been designed to monitor multiple hosts with potentially different 
operating systems, providing centralized logging and maintenance, although it 
can also be used as standalone application on a single host. 

See README.SLACKWARE for setup and configuration information.