mossy832-ga:
Thanks for your Question about modem hi-jacking and whether it poses a
danger when you use a broadband Internet connection.
First, let's define what a modem is. The term "modem" is actually a
made-up word, referring to any device that is a modulator-demodulator
for any form of communications signal. If you take the first two
letters of 'modulator', and the first three of 'demodulator', you have
'modem'.
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http://www.ed.gov/pubs/parents/internet/glossary.html
"MODEM: A device that allows computers to communicate with each other
over telephone lines or other delivery systems by changing digital
signals to telephone signals for transmission and then back to digital
signals. Modems come in different speeds: the higher the speed, the
faster the data is transmitted."
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Originally, the term modem was used solely to describe devices used to
allow computers to connect to each other over telephone lines. Without
getting too deep into the details, there were modems that were
designed for constant connections over special, private telephone
lines, and then there were modems designed to be used with your
'regular' phone line, that could dial up the phone number for another
computer and negotiate a communications session.
These dial-up modems are still used today (as broadband is not yet
available everywhere, at a price point that everyone can afford), and
represents the most popular way in which computer users can access an
Internet service provider. For example, America Online (AOL) still has
about 21 million subscribers to its dial-up service, versus 3 million
for broadband:
http://www.usatoday.com/money/media/2004-04-21-aol-time-warner_x.htm
Now, you mentioned in your comment that your broadband connection uses
a modem too. That is correct, but the modem is not a dial-up modem. In
order for your computer to communicate with other computers over a
cablevision network, or using Digital Subscriber Line (DSL) technology
over a telephone company's network, there is a need for a device to
convert (modulate and demodulate) the communications between the
digital world of the computer, and the analog world outside. So, the
broadband modem is still a modem, but it is NOT a dial-up modem. The
broadband modem is designed to allow your computer to talk over the
private network of your cable or telephone company, and is controlled
by the equipment on that private network. In the case of DSL
technology, the DSL modem is actually sending signals over a part of
the possible frequency range of your telephone wires that is not
normally used by a regular telephone call. The DSL modem can only
communicate with the telephone company's equipment located at the
other end of the phone line, in the telephone company's local
switching station.
Back to hi-jacking. "Modem hi-jacking" is a real danger for anyone who
uses a dial-up modem, over a regular phone line, to access their
Internet service provider. Such users are so used to their computer
dialing a phone number to access the Internet, that they may not
notice if a maliscious program were to change the phone number that
the computer dials. So, instead of making a local call to their ISP's
local point of presence, their computer ends up calling a
pay-per-minute number (in the US, for example, a 1-900 number that has
a per-minute charge of several dollars per minute). The longer the
computer stays on the call, the bigger the surprise when the phone
bill arrives. The bulk of the revenue from the call goes to the
operator of the 1-900 number. Often, these 1-900 numbers are based in
foreign countries, so there is only so much that your phone company
can do for you when you dispute the charge.
Even if you do not normally use a modem for accessing the Internet,
though, you may still be in danger. Many people have a dial-up
fax-modem in their PC, which they use to send and receive faxes. Thes
modems can be hi-jacked by a maliscious dialer program, and used to
call up a pay-per-minute phone number.
The software from stopitnow.com.au is advertised as being able to
prevent any maliscious software from accessing your dial-up modem and
using it against your wishes. However, in your case, where you use a
broadband connection, the best protection against maliscious dialer
programs is simply to not connect any dial-up modem you may have in
your PC to your regular phone line. Then, practice safe Internet
surfing techniques to avoid downloading maliscious dialer programs,
and you will be as safe as you can be. You will also have saved
yourself the cost of the program from stopitnow.com.au. Nothing
against the program; for people who use dial-up modems to connect to
the Internet, software such as this can be a saving grace. For someone
like yourself, though, who does not use a dial-up modem regularly, the
best protection is the physical one of making sure that any dial-up
modem in your PC is not plugged into a phone line. There are also
services offered by some phone companies that allow you to restrict
outgoing long-distance or premium-rate calls, but this often comes at
an additional monthly cost.
I hope this explanation helps; please use the Request Clarification
button above if there is any part of this that you do not fully
understand.
Thanks,
aht-ga
Google Answers Researcher |
