[Freebsd-security] Re: Hacked or not appendice

[Remko Lodder]

Hey

Peter Jeremy wrote:

> 
> [Please wrap your mail before 80 characters]
> 
> Why would you trust the toolchain on a potentially hacked machine?
> There's an old paper by Ken Thompson that dicusses patching the C
> compiler to recognize the login sources and re-introduce a backdoor -
> even it was removed from the login sources.
> 
> You would be much better off booting a fixit CD-ROM and using that
> rather than trusting anything on the potentially hacked system.

Indeed, one should make a backup copy (if possible) of the potentially 
hacked computer (Drive) and take the machine offline.

Then insert the backupdisk in a other pc, (or the same, with the 
original hd stored safely)  and startup your Live-cd kit (which can be a 
freebsd version from cd, or linux). Make sure that the tools necessary 
are on the live cd;-) and to forensics (tct might help (The Coroners 
Toolkit)..


After finding out what happened, format the disk, and reinstall from 
scratch, be hostile to every config file and stuff you backupped, 
because you might not be able to tell when the potential hack took 
place.....


Cheers :-)

> 

-- 
Kind regards,

Remko Lodder                   |remko at elvandar.org
Reporter DSINet                |remko at dsinet.org
Projectleader Mostly-Harmless  |remko at mostly-harmless.nl