Re: Windows Platform Binary Table (WPBT) - BIOS PE backdoor

From: Jerome Athias <>
To: Kevin Beaumont <>
Subject: Re: Windows Platform Binary Table (WPBT) - BIOS PE backdoor

Some more info

2015-08-12 14:44 GMT+03:00 Kevin Beaumont <>:
> There will be debate about if this is a vulnerability.  It affects a
> majority of user PCs -- including all Enterprise editions of Windows,
> there is no way to disable it, and allows direct code execution into
> secure boot sequences.  I believe it is worth discussing.
> Microsoft documented a feature in Windows 8 and above called Windows
> Platform Binary Table.  Up until two days ago, this was a single Word
> document not referenced elsewhere on Google:
> This feature allows a BIOS to deliver the payload of an executable,
> which is run in memory, silently, each time a system is booted.  The
> executable code is run under under Session Manager context (i.e.
> This technique is being used by Lenovo and HP to silently deliver
> software, even after systems are completely wiped.  This issue came to
> light in this forum thread:
> Additionally, the code is injected and executed in Windows after the
> Windows kernel has booted - meaning hard drives are accessible.  In a
> HP document - page
> 18 - they reference they use Windows Platform Binary Table to inject
> their code into encrypted systems (e.g. BitLocker) (!!!!).
> It is not possible to disable this functionality.  If you can gain
> access to the BIOS, you can inject code into the Windows boot sequence
> using the documentation linked above.  The BIOS delivered PE code is
> not countersigned by Microsoft.
> Microsoft say: "If partners intentionally or unintentionally introduce
> malware or unwanted software though the WPBT, Microsoft may remove
> such software through the use of antimalware software.  Software that
> is determined to be malicious may be subject to immediate removal
> without notice."
> However, you are relying on Microsoft being aware of attacks.  Since
> the code is executed in memory and not written to disk prior to
> activation, Windows Defender does not even scan the executed code.

Copyright © 1995-2019 All rights reserved.