Page 260 - DCAP104_EXPOSURE_TO_COMPUTER_DISCPLINES

Unit 14: Taking Protected Measures

How do intruders break into your computer? In some cases, they send you email with a virus. Notes
Reading that email activates the virus, creating an opening that intruders use to enter or access
your computer. In other cases, they take advantage of a flaw or weakness in one of your computer’s
programs - vulnerability—to gain access.
Once they’re on your computer, they often install new programs that let them continue to use your
computer—even after you plug the holes they used to get onto your computer in the first place.
These backdoors are usually cleverly disguised so that they blend in with the other programs
running on your computer. The next section discusses concepts you need to know, especially trust.
The main part of this document explains the specific issues that need your attention. There are
examples of how to do some of these tasks to secure a Microsoft Windows 2000-based computer.
We also provide checklists you can use to record information about the steps you have taken
to secure your computer. Finally, a glossary defines many of the technical terms used in this
document. Unless otherwise stated in the glossary, the definitions come from the Webopedia
Online Dictionary for Computer and Internet Terms. Whether your computer runs Microsoft®
Windows®, Apple’s Mac OS, LINUX, or something else, the issues are the same and will remain
so as new versions of your system are released. The key is to understand the security-related
problems that you need to think about and solve.

14.1 Keeping Your System Safe

Before diving into the tasks you need to do to secure your home computer, let’s first think about
the problem by relating it to something you already know how to do. In this way, you can apply
your experience to this new area.
So, think of your computer as you would your house, your apartment, or your condo. What do
you know about how that living space works, what do you routinely do to keep it secure and
what have you installed to improve its security? (We’ll use this “computer-is-like-a-house-and-
the-things-in-it” analogy throughout, departing only a few times to make a point.)
For example, you know that if you have a loud conversation, folks outside your space can probably
hear you. You also routinely lock the doors and close the windows when you leave, and you
don’t give the keys to just anyone. Some of you may install a security system to complement your
practices. All of these are part of living in your home.

Let’s now apply similar thinking to your home computer. Email, instant messaging, and most web
traffic go across the Internet in the clear; that is, anyone who can capture that information can read
it. These are things you ought to know. You should always select and use strong passwords and
exercise due care when reading all email, especially the unsolicited variety. These are things you
ought to do. Finally, you can add a firewall, an anti-virus program, patches, and file encryption
to improve the level of security on your home computer.

Write down the steps involved in creating password for your computer.
The rest of this document describes the things you ought to know, do, and
install to improve the security of your home computer.

On starting point for solving home computer security problems is being aware
of how the Internet and some of its technologies work. If you know how they
work, you can evaluate solutions to the problems that come up. You can also
use the Internet more safely and responsibly. In this section, we’ll talk about
two topics: trust and information in the clear as it crosses the Internet.

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