Computer Viruses are spread either through email, or like the hackers, they
can scan computers for openings. Once on your computer a virus will
start sending itself out to other computers. Some viruses are written
purely to see how far they will spread, others are written to deliver
a political message, or cause damage, but the most common use of a virus
now is to install software that hands over control of the computer to
the virus writer either for their own purpose or so that they can sell
that access.

The biggest problem affecting Windows computers today is Spyware
and Adware. Spyware is software that runs on your computer without
you knowing and collects information about you. It can look at many
things including how much you use the computer, what programs you use,
what web sites you visit, what adverts you click on, and many other
items of interest to the software writer. The spyware reports back
with all of this information to the company that installed it. Adware
is similiar software that runs in the background, but as well as
collecting information, it displays extra advertisments to you. These
are often in the form of pop-up adverts over the web page that you are
looking at, or even embedded in the web page. Sometimes they are
related to the page you are looking at, or for a competitors product.
More often they are advertising pornographic web sites.

How does Spyware get on my computer?

Spyware and adware are most commonly installed through Microsoft's
Internet Explorer either when the user clicks on an advertising banner
masquerading as a fake computer message, or completely automatically
when the web browser loads a page that links to the software.
Internet Explorer makes it very easy for this software to install
itself without the knowledge of the user through systems called
"Active X" and "Browser Helper Objects."

Adware is also often added to your computer when installing free
software. The adware makers pay the free software writer a fee
to include their software. In these cases the license agreement for
the software usually states what is being done, but very few people
read these agreements. Please note: the vast majority of free and
open source software does not include spyware or adware. Please don't
take away the idea that it is not safe to install free software - as
you will see at the end of this article, some of the best defences
against these problems are free!

But why do they want my computer?

Once malicious software is installed on your computer it can have
several objectives:

• To spread to other computers. This is the primary aim of viruses.
  
• To form part of a Denial of Service attack. This is where
  a hacker will use your computer as one of many to deluge an organisation's internet
  servers with requests for information until they break because of the
  overload. This may be done for political purposes or for extortion.
  
• To give control of the computer to the software author. Once they
  have control they may use it for the purposes below, or they may sell
  the access to someone else for a profit.
  
• To send spam. (Unsolicited Commercial Email.) Spammers would prefer to use your computer rather
  than theirs so that they can send their messages for longer without
  getting shut down.
  
• To sell information about you and your habits to
  advertisers. Spyware provides very profitable information for
  marketing companies to use or sell.
  
• To show you advertisments - either extra pop ups over your web
  browser, or in web pages. Many programs will set your web browser
  home page to a different website in order to accumulate advertising fees.
  
• To get your computer to dial premium rate numbers. Many web sites
  install software that hangs up your modem and reconnects the computer
  to the internet through a premium rate number. This is very
  profitable for the web site and extremely expensive for the user.
  
• To gather personal details for identity theft.
  
• Finally, they may simply steal your financial details such as
  credit card numbers or bank account details. Software installed on
  your computer can see a credit card number even if you are typing it
  into an encrypted web page.
  

What will they do to my computer?

The computer will start up more slowly because of all the malicious
software that it is required to load when it is turned on.

The computer will run very slowly and crash more frequently because
of the large amount of malicious software taking up memory and
processor power. Spyware and adware from competing manufacturers have
even been known to fight over computers! This inevitably causes more crashes.

The internet connection can become unusable because a large portion
of it will be taken up with outgoing viruses and spam emails that are
being sent to other computers. Browsing the web can also be
appallingly slow because the information is being re-routed through
the spyware companies servers so that they can record it.

Many advertisments will be displayed while browsing the internet,
often inappropriate, or pornographic. Sometimes the quantity of
adverts is so overwhelming that the user gives up using the internet.

Sometimes the flood of viruses, spyware and spam can so
overwhelm a computer that the user gives up the computer as broken
forever. The slow starts, random crashes and strange behaviour may
seem like a physically broken computer but often it is really just a
software problem. This happens far more frequently than people think
and in fact their broken computer could have been fixed with one or
two hours of work on the software rather than buying a whole new
computer. If no preventative steps are taken then the new computer
will be in the same position within a few weeks.

Scary stuff

A recent HREF="http://www.pcworld.com/news/article/0,aid,118311,00.asp">survey
by AOL found spyware and adware on 80% of computers
polled, with an average of 93 items per computer! This problem is
huge and the general public is oblivious to it apart from occasionally
wondering why their computers are slower than they should be or why
they see so many adverts.

Some people even think that they must accept spyware in order to
use a modern computer. This is a dangerous position to take as
companies that use spyware are not particularly ethical about what
they do with the data. There will always be alternative free software
that does not require the installation of spyware to work.

The average time for a windows computer not protected by a firewall to be infected is now down to four minutes, and spam distribution from the hacked computer starts within ten hours.
Source: USA Today study

What can I do about it?

A computer running Windows must have the following:

• Firewall hardware (best) or software, or both.
  
• Regularly updated Windows software, either automatically, or
  manually at least once a week.
  
• Anti virus software, updated daily, scanning daily.
  
• Spyware removal software, updated at least monthly, scanning at
  least weekly. This could be relaxed slightly if not using Internet Explorer.
  

It is highly recommended (See the links below) to switch away from Internet Explorer to a
more secure web browser, such as HREf="http://www.spreadfirefox.com/?q=affiliates&id=32832&t=80">Mozilla
Firefox or Opera. This will
prevent most spyware from installing on your computer.


Sources:

CERT (US Computer Emergency Readiness Team) HREF="http://www.kb.cert.org/vuls/id/713878#alt_browser"> recommends using a different web browser

Penn State HREF="http://www.informationweek.com/story/showArticle.jhtml?articleID=55301109&tid=6004">Tells 80,000 Students To Chuck IE

Finnish government tells citizens not to use IE

Slate (Microsofts own online magazine at the time!) HREF="http://slate.msn.com/id/2103152/">recommends Firefox

NY Times HREF="http://www.nytimes.com/2004/12/19/business/yourmoney/19digi.html?oref=login">article on Firefox

There is a very simple rule for reducing infections by computer
viruses: DON'T CLICK ON EMAIL ATTACHMENTS! OK, so that is a little over the
top and sometimes you have to open an email attachment, but stop and
think first. The most common way that a virus will get on to your
computer is through an attachment in an email. How does it get from
the email to your computers memory? Usually, it is because someone
clicked on it.

If you receive an unexpected email from someone and it contains a
program, don't open the program, even if you know the sender. First
check that you were supposed to recieve the program, that you really
need the program, and that your virus scanner thinks it is OK.
Sometimes even a seemingly innocuous attachment such as a picture may
really be a virus. Because of a bug in Microsoft Outlook and Outlook
Express it is
possible for a program file which should end in .exe or .vbs to look like it
is a picture that ends in .jpg and in this way it can fool the user
into opening it.

If you use either Outlook or Outlook express then you can make
things much more secure by turning off the preview function and HTML
mail. This will prevent Outlook from opening web pages that are sent
to you inside emails. If you do not need the calender or groupware
functions of Outlook then I recommend HREF="http://www.mozilla.org/products/thunderbird/">Mozilla
Thunderbird as a better email program.

Recommended software

In order to beat malicious software I recommend that all users of
Microsoft Windows download and install the free software listed below.
See my step-by-step guide for
full instructions on how to install and use all of this.

The first thing that you should install is a firewall. If your
network is not protected by a hardware firewall (a physical box
between your computer and the internet) then you need a software
firewall. I recommend Zone Alarm Personal from HREF="http://www.zonelabs.com/store/content/company/products/znalm/comparison.jsp?lid=ho_za">www.zonelabs.com
(Click on "Free Download" to get the personal version.)

If you are running Windows XP then instead of installing Zone Alarm
you should install Service Pack 2 as soon as possible. Service Pack 2
is a set of updates from Microsoft that include a firewall and many
other enhancements that significantly improve Windows defences
against malicious software. You can download service pack 2 from HREF="http://www.windowsupdate.com/">windows update but it is a
very large download. If you do not have broadband then you can get
Service Pack 2 on CD free of charge from computer shops such as PC
World, from magazine cover disks, or you can order it for free from HREF="http://www.microsoft.com/athome/security/protect/cd/confirm.aspx">Microsoft.

No matter which version of Windows you are using, you should next make
sure that it is up to date by visiting HREF="http://www.windowsupdate.com/">windows update. After you
have done this you should open the control panel on your computer and turn on
automatic updates, or at least automatic notification of updates. If
you do not do this then you should check the
windows update site regularly.

To remove spyware and adware I suggest that you use either Spybot
Search and Destroy from HREF="http://www.spybot.info/">www.spybot.info
or Ad-Aware
Personal from HREF="http://www.lavasoft.de/software/adaware/">www.lavasoft.de
Sometimes you may need to use both if you have particularly stubborn
spyware.

To protect your PC from viruses you can use AVG Anti-Virus Free Edition HREF="http://free.grisoft.com/freeweb.php/doc/2/">www.grisoft.com

To prevent spyware from installing itself through your web browser I
recommend that you use Mozilla Firefox from HREf="http://www.spreadfirefox.com/?q=affiliates&id=32832&t=80">www.getfirefox.com.
After installing Firefox you may need to update your HREF="http://plugindoc.mozdev.org/faqs/firefox-windows.html">plugins
such as Java, Flash, Quicktime and Real Player.

Mozilla Thunderbird from HREF="http://www.mozilla.org/products/thunderbird/">www.mozilla.org/products/thunderbird/
is the companion email program to Firefox. Once installed you should
configure it to filter out junk email and turn off the automatic
diaplying of HTML mail, this will prevent spammers from tracking your
reading of their emails.

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