full-disclosure - Bios programming...

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From: matt at dynamicanswers.com (Matt Marooney)
Subject: Bios programming... 

Hmm... That's all true... Especially the motivated user part :)

I'm banking on the probability that most people don't even know what a
BIOS is.  If they go to a site, and sign up for the service, after
entering their info, and email recipients, they would be prompted to
continue and download a small piece of software onto their computer.
The user would be assured that the software would not interfere with
their normal computer use (and it won't) and that's that.  They would
have no idea how the program is working, or where the program resides.  

This ignorance, should, IMHO, keep MOST people from figuring out how to
remove it (except you and me and everyone else on this list ;))  

I want to exploit the fact that they don't know which protocols are
being monitored, so they will be afraid to try to get around it.
Psychologically, the unknown will be more of a deterrent than anything
else.   

I know that I have had a bear of a time removing spyware in the past,
maybe we can leverage that technology for good somehow.  

-----Original Message-----
From: Valdis.Kletnieks@...edu [mailto:Valdis.Kletnieks@...edu] 
Sent: Thursday, March 03, 2005 3:57 PM
To: Matt Marooney
Cc: full-disclosure@...ts.netsys.com
Subject: Re: [Full-Disclosure] Bios programming... 

On Thu, 03 Mar 2005 15:33:09 EST, Matt Marooney said:

> The intent of the BIOS portion of the program was just to have a small

> bit of code that checked for the existence of the main monitoring 
> program on the disk, and if it was not there, reload it somehow.
> 
> The main program would run from the disk, not the BIOS.

Like I said - all it takes is a Knoppix disk to screw over most of these
schemes - you can't even disable booting from CD and put a BIOS password
on, because you have the following:

1) A motivated user

2) Unmonitored, unobserved physical access (if you don't, there's
*bigger* problems in this scenario ;)

3) Somewhere in there, there's a jumper that will reset the BIOS
password....

There's really *NO* way to do this on today's commodity hardware in a
way that will stop a user who knows it's there and has physical access.
At best, you can do it in a way that will surprise an *unsuspecting*
person (which is what most of these anti-theft beacon programs do - the
only reason they work is because the guy who jacked the laptop probably
doesn't realize the program is installed, and thus doesn't take
precautions to stop it).

The only way you can make this work is if you have hardware that
includes something like the TPM chipsets from NatSemi or Atmel.
Unfortunately, if your operating system contains enough support for the
chipset to use it so the person at the keyboard can't subvert it, it
will almost certainly use it *itself* to stop people from doing exactly
the sort of code insertion you're trying to do.

So you're *still* screwed. :)