nabou is a Perl program which can be used to monitor file changes and directories on your system using MD5 checksums. It can also monitor crontab entries, suid files, user accounts, listening TCP/UDP ports, and processes. Nabou stores all data in standard dbm databases. Encrypted databases are supported using RSA public key encryption. Nabou is highly configurable; you can exclude files from being checked, configure which file attributes it should look for, use custom checks, and much more.
