March 31, 2011
Malicious Software 1
I. Malicious software
A. How hackers infect personal computers
3. Trojan horses
B. Reasons hackers infect computers
C. Defending against malicious software
1. Antivirus programs
Malicious Software 2
For people who own a computer, the idea of being infected
with a computer virus is both dreaded and hated. Early signs of
damage appear the moment the computer starts doing strange
things such as slowing down or not opening some files and
programs. Not only is an infected computer annoying, it can also
lead to a waste of precious time, effort, and money. If left
unchecked, it could destroy many things, from important files
and documents to the computer unit itself. This paper is about
how hackers infect computers, why they do it, and how to defend
against malicious attacks.
Hackers can infect computers in many ways. The most common
infections include maleware, worms, Trojan horses, viruses,
phishing, pharming, spoofing, and spyware. Each steals
information from personal computers, but in different ways.
Malware stands for malicious software, which means its
purpose is to cause harm within a computer unit. “Malware is
software that will get into your system or your computer and
maybe set off a series of things like Trojan horses, worms, and
viruses” (Hacker X). It has the ability to monitor a person’s
activity, bombard them with pop-up ads, and make their computer
virtually impossible to use (Baratz).
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A computer worm is a software program that is designed to copy
itself automatically from one computer to another, without human
interaction. Unlike a computer virus, they do not attach themselves to
other files or programs. They infect a node, which is a collection of
servers. The servers connect many people’s computers to the node and
that is how the worm spreads (Hacker X). Once a worm gets into a
computer unit it can erase programs or information. The worm consumes
a lot of system memory, which causes the computer to become slow and
it may even stop it from responding. The biggest danger with a worm
is its capability to replicate itself. Instead of sending out a
single worm, it sends out hundreds or thousands.
A Trojan horse is a disguised software program. The term
comes from the Greek story of the Trojan War. Commonly people
will download a Trojan horse disguised as a useful program or
even a program advertised to get rid of malicious software.
Unlike worms or viruses, a Trojan horse does not replicate or
reproduce. A Trojan horse deals damage by deleting files and
destroying information on computer systems. Also, they are known
to open up computers to malicious users, allowing confidential
or personal information to be compromised (Beal).
Computer viruses are small software programs that are
designed to spread from one computer to another and to interfere
with computer operation. They are most commonly spread through
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attachments in e-mail messages. Many viruses do nothing more
than display a message or make sounds just for the sake of being
annoying. But, there can be several symptoms due to viruses,
such as computers running slower than usual, restarting on their
own, displaying unusual error messages, not responding, or
freezing frequently (Microsoft).
Phishing occurs when the thief sends out an email posing as
a trustworthy source. This legitimate-looking email is an
attempt to gather personal and financial information from
recipients. The email will often contain a link or direct people
to a website asking for updated personal information, such as
passwords and credit card, social security, and bank account
numbers that the legitimate organization already has
Similar to phishing, pharming is another form of online
fraud. Pharmers use the same fake websites to create online
scams, but are more difficult to detect in many ways because
they do not rely on the victim to click on a fake link. Pharming
instead compromises host files and then converts URLs (Uniform
Resource Locator) into the code needed to access websites. Then,
when they type in a website address, they are redirected to a
fake website (Norton).
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Spoofing is the act of sending an email to a recipient, or
a group of recipients, by disguising the sender's identification
and making it look like it came from someone else. This is
basically meant to fool the recipient into opening the email,
possibly resulting in opening a dangerous virus.
Spyware is computer software that obtains information from
a user's computer without the user's knowledge or consent,
usually for advertising purposes. Just like a Trojan horse,
spyware is downloaded without actually knowing it. Because
spyware takes up a lot of bandwidth it can cause the computer to
slow down or crash. Spyware is also capable of tracking
keystrokes and browsing the hard drive. Other kinds of spyware
can change your web browser’s homepage or add things not needed
or wanted (Microsoft).
Just as there are a variety of ways to infect computers,
hackers have a variety of reasons for doing so. “True hackers
simply want the challenge of getting the information by phishing
or breaking into a system and 99.9% of the time that's as far as
it's going to go” (Hacker X). Often, the reason is the challenge
of getting into someone’s personal computer. It is not
necessarily about being malicious or obtaining money. Hackers
like the challenge of creating a virus or similar malicious
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software to have the best virus and to beat antivirus companies.
(As well as testing it on unsuspecting prey.)
Of course there are people that do it for financial
reasons. They use personal information to buy and sell for
profit. Some may use key logging that allows them to track what
keys are pressed. Using this technique they can get a hold of
credit card numbers and passwords. Hackers can also use ads to
trick people into paying for items that they will not actually
Sometimes malicious software is created for the purpose of
making a statement. Hackers may want to interfere with
governmental or other public service website operations. The
hacker’s motivation might be to make political or value
statements related to disagreements they have with those
websites in some shape or form.
Just as there are ways to cause harm, there are ways to
defend against it. Refrain from opening emails, especially
attachments, from suspicious unknown senders. Using strong
passwords and keeping them secret. And protect the safety of
files with valuable information by using antivirus programs that
have a variety of features, such as firewalls, safe search, and
pop up blockers.
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There is a great variety of antivirus programs such as AVG
Antivirus, Norton, and McAfee. These programs protect from
hackers, phishing scams, adware and malware that come through
email or IM. AVG even scans outbound email to make sure people
don’t accidentally pass a virus along to others. And of course
the software protects from other forms of malware, including
worms, key loggers, and Trojans.
Strong passwords are at least 14 characters long and
include a combination of letters, numbers, and symbols. Don't
share passwords with anyone. The same password should not be
used on all sites, because if it is stolen, all the information
it protects is at risk. And to be extra safe create different
passwords for the router and the wireless key of your wireless
connection at home.
In summary, hackers can cause malicious damage to personal
computers for reasons such as challenge and greed. To protect
personal computers from malicious software, avoid opening
emails, especially attachments, from suspicious unknown senders.
And protect the safety of files with valuable information by
using antivirus programs that have a variety of features, such
as firewalls, safe search, and pop up blockers.
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Baratz, Adam. "Malware: What It Is and How to Prevent It." Ars
Technica. 11 Nov. 2004. Web. 25 Jan. 2011.
Beal, Vangie. "The Difference Between a Virus, Worm and Trojan
Horse - Webopedia.com." Webopedia: Online Computer
Dictionary for Computer and Internet Terms and Definitions.
29 June 2010. Web. 01 Mar. 2011.
Hacker X. "Computer Security And Malicious Software (Viruses,
Hackers & Spam)." Videojug - Get Good At Life. The World’s
Best How to Videos plus Free Expert Advice and Tutorials.
Web. 25 Jan. 2011.
Microsoft. "Spyware | Prevent Spyware | Unwanted Software |
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Microsoft Security." Microsoft Security. Web. 26 Jan. 2011.
Norton. "Pharming - Online Fraud | Cybercrime." Spyware Blockers
- Virus Protection | Norton. Web. 26 Jan. 2011.
Webopedia. "What Is Phishing? - A Word Definition From the
Webopedia Computer Dictionary." Webopedia: Online Computer
Dictionary for Computer and Internet Terms and Definitions.
Web. 01 Mar. 2011.