Security For Ordinary PC Users
Wendy Tate
and Farida Ali of Dynamic Computer Corporation
Most security articles are
written for network administrators charged with the security and
availability of corporate networks. As computers have become a
pervasive tool in the office, however, they have begun to be an
indispensable one at home as well. Around 73% of US homes have a PC
in them, and about half of US homes have broadband internet service
of one type or another. Many of us are also administering second or
third PCs for children, teens, or elderly relatives. While the home
PC should definitely not contain corporate secrets, they do
safeguard some data close to users' hearts. Imagine how it would
feel to lose your family photos, tax records, little Janie's
homework projects, emails from great-grandpa, your confirmations and
boarding passes for next week's vacation and your grandma's recipe
book all in one blow. The data on that home computer is important to
you, if not to the network administrator at your office.
Why would anyone attack
your home PC? Simply put, there is a great deal of money to be made
by enslaving your computer and using it for nefarious purposes, such
as sending SPAM for profit, distributing illegal files, or hacking
other networks. Some hackers make a great deal of money by stealing
your financial and personal information, and either reselling it to
other criminals or using it to make purchases themselves. Either
way, a large percentage of PC attacks are made for profit. Frankly,
home computers tend to be easy targets, since they don't have
professional defenders like corporate networks do.
So, without a
professional defender, how can you go about assuring your computer
and the rest of your family's PCs are secure? Here are some
recommendations.
1. First, you should
definitely consult your system support personnel if you work from
home. If you use your broadband access to connect to your employer's
network via a Virtual Private Network (VPN) or other means, your
employer may have policies or procedures relating to the security of
your home network. Those should supersede what you are reading here,
so be sure to consult with your employer's support personnel, as
appropriate, before following any of the steps outlined in this
document. You can use the information below to prompt discussions
with support staff, or to help you administer other family
computers.
2. Use virus protection
software and anti-spyware software. Anti-virus software is a
must-have for all Internet-connected computers. Inexpensive AV
software often comes packed with your new PC. Be sure to keep your
anti-virus software up-to-date, using automatic updates when
available. Depending on the software you choose, you may also need
to renew your subscription annually to keep receiving updates. If
you do not renew your subscription, you may as well not have
antivirus software at all. If AV software is not up to date, it
absolutely cannot work properly. Antispyware software has also
become important as more and more hacks are delivered in rootkits
and other non-viral means.
3. Use a firewall.
There are two types of firewalls; a hardware firewall, which is a
network appliance, or a software-based firewall, which runs on your
computer. Intruders are constantly scanning home user systems for
known vulnerabilities. Firewalls (whether software or
hardware-based) can provide some degree of protection against these
attacks. Software firewalls need to be kept up to date when
manufacturers release patches to correct flaws or security holes. A
firewall is never infallible, so it is important to continue all the
other security measures after it is installed. It's also best not to
'poke holes' in your firewall if you can avoid it. If you find
yourself digging through the settings to open ports without knowing
exactly why you are doing it, it is time to reconsider. Most good
software for the PC these days is designed to work through firewalls
without disabling them. If you've downloaded a software package that
is being blocked by your firewall, it's a good idea to check online
for reviews of that software and make sure it's safe to use.
4. Don't open email
attachments unless you can verify they are legitimate. Before
opening any attachment, be sure you know the source of the
attachment. It is not enough that the email originated from an
address you recognize, because many hacks are specifically designed
to utilize familiar email addresses to disguise their true points of
origin. If you are in doubt, ask the other person whether they have
sent you an attachment purposefully. Any good net citizen will be
happy to verify their attachment for you.
5. Don't run programs
of unknown origin. Never run a program unless you know it to be
authored by a person or company that you trust. Also, don't send
programs of unknown origin to your friends or coworkers simply
because they are amusing -- they might contain a Trojan horse
program or a rootkit. If you are wondering whether to install a
program, you should try to investigate it first. There are a great
many authors who post excellent software reviews online. Try running
a google search on the name of the software and the word 'review'.
This should give you some idea whether or not the software is legit.
If you can't find a decent review, odds are you shouldn't run the
software.
6. Keep all
applications, including your operating system, completely patched.
Vendors will usually release patches for their software when a
vulnerability has been discovered. Read the manuals or browse the
vendor's web site to make sure you understand how to keep the
software current. Some applications will automatically check for
available updates, and many vendors offer automatic notification of
updates via a mailing list. Look on your vendor's web site for
information about automatic notification. If no mailing list or
other automated notification mechanism is offered you may need to
check periodically for updates. If the PC has been turned off for a
few weeks while you were away, the first thing you should do is
update your software when you turn it back on. The key with updates
is that they need to be performed frequently enough to 'patch'
security holes before they can be exploited. Make it a rule in your
house that Windows Update should always be allowed to do whatever it
wants, and that the kids aren't allowed to interrupt that process.
If a reboot is required, it should be performed right away.
7. Turn off your
computer or disconnect from the network when you are not using it.
An intruder cannot attack your computer if it is powered off or
otherwise completely disconnected from the network. This will also
save you money on your energy bill, and may extend the lifespan of
your computer.
8. Disable Java,
JavaScript, and ActiveX if possible. Be aware of the risks involved
in the use of "mobile code" such as ActiveX, Java, and JavaScript. A
malicious web developer may attach a script to something sent to a
web site, such as a URL, an element in a form, or a database
inquiry. Later, when the web site responds to you, the malicious
script is transferred to your browser. Unfortunately, many
legitimate sites use scripts running within the browser to add
useful features. Disabling scripting may degrade the functionality
of these sites. Detailed instructions for disabling browser
scripting languages are available in
http://www.cert.org/tech_tips/malicious_code_FAQ.html .
More information on ActiveX security, including recommendations for
users who administer their own computers, is available in
http://www.cert.org/archive/pdf/activeX_report.pdf .
9. Disable scripting
features in email programs. Because many email programs use the same
code as web browsers to display HTML, vulnerabilities that affect
ActiveX, Java, and JavaScript are often applicable to email as well
as web pages.
10. Make regular
backups of your data. Here are the basics of data backups:
A. In order to create good backups, you need to know where your
files are. Organize them in some way; by type, by title, by date; it
doesn't matter. It's best to store your files in a directory you
create yourself, or in your “My Documents” folder.
B. Make a copy of your files on an external device. Since you know
where the files are, you can simply copy entire directories and
manually paste them to your backup location. Alternatively, you can
use backup software, which will perform these functions for you
automatically. For your backup location, you can use removable media
such as ZIP disks or recordable CD-ROM disks (CD-R or CD-RW disks),
an external hard drive, flash media, or any type of device on which
you can store data outside the PC's case. Be sure to store the
backup copy somewhere away from the computer. Send a copy to a
friend for safekeeping, or put it in your safety deposit box at the
bank. If you want your data to survive a house fire, you will need
to store a copy away from the house.
C. Make a routine for backups to occur with regularity. If you don't
save new files to your computer very often, you don't need to
perform backups terribly often, either. If, however, you are adding
photos of the new baby daily, you should make your backups more
frequently.
11. Make a boot disk in
case your computer is damaged or compromised. To aid in recovering
from a security breach or hard disk failure, create a boot disk on a
floppy disk which will help when recovering a computer after such an
event has occurred. Remember, however, you must create this disk
before you have a security event. For information on creating a boot
disk, check your operating system vendor's web site.
12. Review your
computer security plans with all the users of the computer. It's
important to make sure everyone is playing for your team, and that
no one is shutting off the firewall or delaying Windows from
performing updates. They also need to know how to avoid downloading
malicious software.
13. Prepare everyone in
the home for social engineering attacks. A social engineering attack
uses persuasion and coercion to convince users to allow access to a
hacker. Unfortunately, awareness of social engineering is low, and
surveys have revealed that nine out of ten people will give their
password in exchange for a chocolate Easter egg. Tell your family
that they should never share their passwords or give out their
personal information online. Try to familiarize them with phishing
tactics, too.
Unfortunately, good PC
security will only defend your PC from data-based attacks. If you
have children or elderly folks at home using the computer, you
should be aware that they are preferred targets for the worst types
of internet predators. In this case it is not just your data or your
computer you must protect, but also your loved ones themselves. In
the case of children, you should make sure they will absolutely
never share their name, address or city, phone number, or the name
of their school, their travel plans or schedule, or where they like
to play. Make sure kids know they should invent usernames that do
not resemble their real names or reveal any personal information.
Inform your kids that they should never agree to meet an internet
friend in person, and that people on the internet might not be what
they seem. If anyone on the internet is being pushy with them, or
making them feel uncomfortable in any way, they should report it to
you immediately. Consider installing software to monitor your kids
online, and make sure you're checking on them to make sure
everything is okay.
The elderly are often
targeted by a different breed of cybercriminal, who will attempt
various cons to perform identity theft, financial theft, and other
types of fraud. Respectfully recommend that your elderly loved ones
check the FTC's web site at
http://onguardonline.gov/index.html. This will give them many
tools to detect and avoid the types of scams often aimed at them |