I’ve a couple of fedora boxes that were coming up with this error when rkhunter was run.

Rootkit Hunter 1.2.8 is running
Determining OS… Unknown
Warning: This operating system is not fully supported!

Seems you just need to add a suitable line into /var/rkhunter/db/os.dat so rkhunter can find your md5 hashes again and properly verify them. e.g.

705:Fedora Core release 5 (Bordeaux) (i386):/usr/bin/md5sum:/bin:

or
706:Fedora Core release 6 (Zod) (i386):/usr/bin/md5sum:/bin:
References
http://www.webhostingtalk.com/showthread.php?t=497209

Categories: LAMP

Jonathan Adjei

Jon's expertise in web development is legendary and he oversees all technical aspects of our projects from development to hosting (all through the command line!) Jon is excited by the latest techniques and keeps the company on track by finding ways to adopt new practices into our workflow.