This collection here will grow and grow. And be sure and thank FastLane , my ISP, for providing the space for these files. The UNIX security checker by Dan Farmer. Run this on your systems before someone else does. Check your firewall before someone else does.
Remote rules list determination for packet-filtering devices.
Many extra features. Written by Simple Nomad. Requires Libnet and libpcap. Dated but still valuable. The poor man's Tripwire.