Eavesdropping a fax machine

Here's an article from back in 2009 that rings a bell:

http://news.bbc.co.uk/2/hi/technology/8147534.stm

Basically, the shared ground of the local electrical infrastructure of any given building may act as an antenna, and allow attackers to detect EM keystroke signals that can be detected on the power plug.

  They demonstrated it working over 
  distances of 1, 5, 10 and 15m from a 
  target, far enough to suggest it could 
  work in a hotel or office.

I think this is the doc from presentation:

http://www.blackhat.com/presentations/bh-usa-09/BARISANI/BHU...

Sounds like the technique is similar for fax machines.

A few months ago (I think it was here on HN) I found a MIT paper that explains how to reconstruct what a old dot matrix printer is printing only by recording and analyzing the sound it makes. The idea is kinda fascinating - at least to me.

A few years back I bought a used HP volume laser printer on ebay. When I went to configure it it had some existing ip addresses entered and when I checked they trace back to the CIA or the NSA (honesty can't remember which but it was one or the other).

Reading this post got me thinking

a) you would think they would have flushed that from the machine before giving to a third party (where I purchased from).

b) I would imagine that some agency (not necessarily of our government) could sell used equipment with the express intent of modifying in some way to collect info. Possibly even target (ala the dropped usb in a parking lot) specific companies or individuals.

Reminds me of Van Eck Phreaking. http://en.wikipedia.org/wiki/Van_Eck_phreaking

When I first read about it as a kid, I was in awe.

See also: optical TEMPEST eavesdropping on a CRT using a high-speed photosensor and a telescope:

http://www.rootsecure.net/content/downloads/pdf/optical_temp...

I wonder how long it's going to take until we have some details from the reverse engineering of the bugs they find in those fax machines...