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Re: FAX a virus
From: Andrew Wheeler <prime_dreamer () yahoo co uk>
Date: Fri, 02 Mar 2007 22:52:38 +0000

Hello,

When you say 
My FAX server allows me to receive faxes from my clients from Internet.

Are you talking about faxes being routed via H.323/SIP or incoming faxes
being forwarded from a fax machine to a folder or email address.

This is an extract from a manufacturers core technology manual.

IETF (Internet Engineering Task Force) and ITU-T have standardized
procedures for sending fax messages over the Internet as e-mail
attachments.
The message is sent as a TIFF-F format image file attached to a MIME
format e-mail message.
(Some older models can also send DCX image files, depending on a user
setting).
To receive a fax by e-mail, a MIME-compatible mail reader is needed. To
view the fax, a TIFF-F viewer is needed. (For some models, the viewer
should also be able to view DCX files.)
The NIC fax must be connected to a LAN and set up correctly in order to
use Internet fax functions.
There is no need to set up a special server. Existing servers on the LAN
can be used. 

If you have not already guest I am a field service engineer and work
with faxes copiers and printers.
Most machines today are hybrids and can do everything. This is not the
first time I have seen this question being asked. A few years ago we
quoted a government department and they had to do a security review on
any piece of equipment that connected to their network (printer) and had
access to the telephone network (fax). They required a letter from the
Manufacturer stating that it was impossible to access the network from
the fax line.

Since then more and more features have been added and I have wondered
about the security implications. Some of the new machines can run
embedded Java applications but require a specially coded SD card and
physical access to install on to the machines(I think the manufacturers
are scared that someone will write a sniffer like program and install it
onto a machine)

I work with machines that can be set up on the local network to receive
faxes over the Internet then forward them via smtp to a users in-box,an
FTP server or to a windows share. The machines I work with run netbsd as
the operating system.

Some machines do allow remote firmware updates mostly via ftp. I also
know of some manufacturers that can remotely connect to a facsimile
machine via the telephone line and adjust the programming (everything
from the quick dials to the fax modem speeds) 

I do not know if sending a virus is possible as the machines only deal
with images but with all the other options I am sure someone might see a
possible security problem.

Andrew

On Thu, 2007-03-01 at 10:07 +0530, Alcides wrote:
Hi lists,
My FAX server allows me to receive faxes from my clients from Internet.
My clients send me some documents using their built-in Fax Printer on 
their PC. My fax server routes the stuff to the document processing 
applications. The document processing system extracts various data 
fields from received portable document format files.
The whole scenario is windows environment and let's assume that virus 
protection is temporarily off.

Now, I have a query:
Can anyone send a fax that includes a file infected with the virus/ worm 
operates as a VBS script embedded within a PDF/TIF file to cause 
infections to my computers/ to affect my FAX system?
What about other possibilities of "the bad guys" using some joiner (or 
wrapper as some say) to bind malware (trojan server etc) with the pdf/ 
TIF files and fax it to me?
I would be very greatful to know what are the various possibilities.

Warm regards,
Alcides.

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