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Re: Any solution for a virus in the BIOS?
From: Ansgar -59cobalt- Wiechers <bugtraq () planetcobalt net>
Date: Mon, 3 Dec 2007 22:02:57 +0100

On 2007-12-03 Michael R. Martinez wrote:
On Mon, 3 Dec 2007 19:40:00 Ansgar -59cobalt- Wiechers wrote:
On 2007-12-02 admin () lh com wrote:
Get a av that has boot sector protection. Once you've run a scan
with that, it will clear things out.

Please explain how boot sector protection is supposed to help against
malware living in the BIOS. You do realize that it's the BIOS that
executes the boot code, don't you?

Assuming the BIOS actually is infected (which isn't too clear after
the OP's rather vague description) the appropriate way would be to
replace the BIOS chip or flash a clean BIOS onto it using a dedicated
device (*not* a PC that is booted with the potentially infected
BIOS). Also examine the supposedly infected harddisk from a clean
system, either by booting some live-CD after cleaning the BIOS or by
attaching the disk to another system (as secondary/external disk).

Boot into a disk that scans for virus at boot!

And then what? In case you didn't notice: the BIOS starts the OS on that
disk too, meaning that malware in said BIOS can also manipulate that OS
and thus any software it may run, meaning that despite booting from a
clean media you still have a (potentially) compromised system.

Ansgar Wiechers
"All vulnerabilities deserve a public fear period prior to patches
becoming available."
--Jason Coombs on Bugtraq

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