Since intruders have something obvious to gain??”
namely, free Internet??”and since wireless networks can be
easy to break into if they??™re not secured properly, this is a
real concern. See ???Set Up a Wireless Router,??? earlier in this
chapter, for details. See also ???Connect to a Public Wireless
Network??? (earlier in this chapter as well) for ways to protect
your computer and your workgroup if you??™re using someone
else??™s Internet connection.
Secure Your Networked PC | 413
Networking and
Internet
An automated invasion by a virus, worm, Trojan horse, or robot
A virus is simply a computer program that is designed to duplicate itself
with the purpose of infecting as many computers as possible. If your
computer is infected by a virus, it may use your network connection to
infect other computers; likewise, if another computer on your network
is infected, your computer is vulnerable to infection. The same goes for
Internet connections, although the method of transport in this case is
typically an infected email message. (See Chapter 6 for complete coverage
of viruses, worms, Trojan horses, and spyware.)
There also exist so-called robots, programs that are designed to scan
large groups of IP addresses, looking for vulnerabilities. The motive for
such a program can be anything from exploitation of credit card numbers
or other sensitive information to the creation of a ???zombie,??? a PC
that has been hijacked for the purpose of distributing spam, viruses, or
extreme right-wing propaganda.
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