“I haven’t tried this, and I don’t know if it will work. I’m not sure how hard it would be to make it work."

But that's the whole crux of the matter. It might be that his machine was compromised via a DOCX but it's unfortunately just speculation without an example. Someone should ask Rex Ballard for more info.

Are OLE files available via OPC reference conventions? If not then this post http://www.robweir.com/blog/2008/03/ooxml-macros-and-security.html might have some implications for OLE too. That would be more fundamental.

Here is the original post on the newsgroup comp.os.linux.advocacy:

Message-ID: <moc.spuorgelgoog.xsh0002g52|9a63dbe8843e-e9e9-5174-7e9d-96166a13#moc.spuorgelgoog.xsh0002g52|9a63dbe8843e-e9e9-5174-7e9d-96166a13>
From: Rex Ballard <moc.liamg|drallab.xer#moc.liamg|drallab.xer>
Newsgroups: comp.os.linux.advocacy
Subject: Re: Leaked ISO Document Reveals Crooked ISO Amid MS OOXML Corruptions
Date: Sat, 12 Jul 2008 08:20:23 -0700 (PDT)

[…]

ODF is a comprehensive document that provides detailed specifications
from the high level document content down to the smallest elements of
scalable vector graphics. There are some “standard” mime object types
that are supported, such as PNG and JPEG, but other embedded formats
must be installed using plug-ins which have to be authenticated by the
user and by the system at installation time, and cannot be installed
by the content. Furthermore, the installed content can easily be
identified as trustworthy or not, and can be restricted in it’s
capabilities.

OpenXML on the other hand, is a high-level specification which
describes the high level envelopes used to embed binary objects which
are included in the content. The content itself contains the binary
code which can call any function in any Microsoft library and has all
permissions of the person opening the document. If a user account is
set up as “Administrator”, then the application can mess with the
registry, create, download, and hide files, can execute applications
in those files, can install any number of new viruses, and generally
wreak havoc on the system.

I’ll leave it to others to document the exact details (as I said, I’m
busy these days), but I’m sure anyone who tries to publish these
vulnerabilites will probably find themselves getting the same
treatment that Tracy Reed of Ultraviolet.org got when he tried to
publish his warnings about ActiveX controls back in 1997. Microsoft
got a court injunction against him, and forced him to take down the
content, claiming that it was being used to encourage hacking, and was
damaging the Microsoft brand.

“I got a couple of docx documents and had trouble getting them to open, even with the plug-in for Office XP. Next thing I know, I get a notice from my registry auditor that I have 1300 new registry errors.”Over the last 10 years,
we’ve seen these very same techniques, documented back in 1997,used widely to spread viruses including
Melissa, Nimda, Sky, BugBear, and about
250,000 other viruses, worms,
and malware, not including spy-ware and
other “Microsoft Authorized”
invasions of our privacy.

I got a couple of docx documents and had trouble getting them to open,
even with the plug-in for Office XP. Next thing I know, I get a
notice from my registry auditor that I have 1300 new registry errors.
And suddenly, my PC is churning the disk-drive and the network
connection at 3:00 AM (I’m getting old and have to get up), and the
network shows that I’m uploading something at full speed, even though
my computer is supposedly sleeping.

It isn’t a back-up program that I’m running.

I would encourage COLA readers and OSS advocates to explore this in
more detail.

get someone with Office 2007 to send you a docx file.
unzip it using pkzip or winzip or unzip.

look at the binary files.

replace one binary object with another.

zip up the document,

see if your office-2007 user can read the “enhanced” document.

For those of you with OLE programming skills, create an OLE object
that creates a file, and e-mails that file to you using smtp.

Send a document with this new ole object embedded (along with the
others) and see if you get an e-mail.

I haven’t tried this, and I don’t know if it will work. I’m not sure
how hard it would be to make it work. I just think it might be an
interesting project worth investigating, especially if you are
considering the migration of a few thousand users to Vista and Office
2007.

I’d love to see what the results turn out to be. After all, if it’s
that easy to take control of a recipient’s machine just by sending
them a “trusted” Word, Excel, or PowerPoint attachment, just think how
much chaos a really aggressive malicious hacker, with a goal of
obtaining marketable information about your business, could do.