Executable Checksumming in OpenBSD 3.0

Contributed by Dengue on 2002-04-19 from the cool dept.

"The folks over at Trojanproof.org have released a paper (pdf) and source code (currently i386 only) about in-kernel MD5Sum comparisons at run time. The purpose? To help you detect binaries that have possibly been tampered with by an intruder."

(Comments are closed)

Comments

By Anonymous () on 2002-04-19 03:00

I'm sorry, but if someone hacks your machine and you have loadable kernel modules enabled, you're screwed. MD5 checksumming in the kernel isn't helpful as, a kernel module can just tell that piece of code "These aren't the droids you're looking for". The only effective method against rootkits is either a.) disable lkm's (not an option for everyone) and b.) An email gets sent to you anytime a module gets loaded/unloaded. Option b won't prevent the root kit from being loaded, but it will let you know about it.
By Bruj0 () on 2002-04-19 03:28

You mean something like this
By Anonymous Coward () on 2002-04-20 01:27

If the machine has all/most important binaries/files with schg flags set and is in securelevel 2, with an mtree sha1digest snapshot sitting on a floppy, and usualy best practices are in use, is there any need for this ?
By Anonymous Coward () on 2002-04-20 06:58 http://mail-index.netbsd.org/tech-kern/1999/06/11/

A trial implementation was done for NetBSD some
time ago by Brett Lymn and a paper on it presented
at AUUG 2000.
By Jedi/Sector One () j@pureftpd.org on 2002-04-20 14:10 http://www.pureftpd.org

Isn't checksumming one of the reason why extended attributes (man extattrl(8) on -current) were introduced?

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