|
|
| |
| |
 |
|
Warning |
|
 |
|
| |
|
You should only contact us from a telephone outside of
the potentially compromised location! DO NOT call
from your office or home; use your cell telephone only
from a discreet location. |
|
|
|
| |
|
|
|
Most people use the term "bug" when discussing
the various ways in which information can be
extracted from an area, . This is generally an all
inclusive term which encompasses everything placed
on the telephone lines. In reality, there are two
different types of attack with two different names.
How should they be described?
In the simplest description, a "bug" is generally an
externally powered device which radiates (transmits)
a signal containing intelligence, whereas a "tap" is
an attachment normally made to a pair of lines for
the purpose of recording or monitoring intelligence,
be it audio, video or data.
In describing a "tap", generally the first thing
that comes to mind is the telephone tap. As
glamorized on television, it is thought of as a
"drop-in" microphone which transmits the
conversation taking place within a room. This method
of attack is, in reality, a "bug" and not a "tap".
Also, on occasion, we see on television the
eavesdropper sitting in an office or basement with
headphones listening to conversations on the
telephone. This is a fairly true representation of
what happens, but there are more ways of "tapping".
They can range from the crude attack hooking a
sound-powered telephone repairman’s handset directly
to the lines, to the more sophisticated method of
using a high impedance device between the lines and
a recorder or amplifier, to using an inductive
device in which the telephone or lines are not
physically altered.
If the telephone instrument has not been modified,
then the only time it can be monitored is when the
telephone is in actual use. However, with any one of
a number of simple to sophisticated attacks, it is
possible to "listen in" at all times to everything
that is being said in the vicinity of the telephone.
Eavesdroppers can install in-line "series" or
"parallel" transmitters on the telephone line in
which no external power supplies are necessary -
power is taken from the telephone lines. No antenna
or microphone is required. These devices can be
placed at any point along the telephone line and
from the telephone to the nearest switching
equipment. They can be as large as the cover on a
fountain pen or they can be as small as a dime.
The operating frequency can range from as low as 30
MHz to over 1200 MHz. That is not to say this is the
only range of frequencies in which they will be
found, only that it is easier to build the devices
to operate within these ranges.
Other attacks that can be made on the telephone
include the manipulation (bending) of contacts on
the hookswitch, the addition of jumpers in the
telephone, or the installation of resistors or
capacitors. These attacks will allow your
conversations to be monitored regardless of whether
the telephone is on hook or not.
The techniques discussed above are not to be
considered the only attacks possible to a telephone
system. They are just a representative sampling. |
|
