1

• Include:– a virus requires a host program

• a worm is an independent program

– a virus modifies other programs• a worm usually does not

– a virus only executes when the host program is running

• a worm is always active

2

• Include:– a virus uses host programs to replicate

• a worm replicates itself over a network– a virus needs to be activated or downloaded (such

as a virus sent through e-mail, it must be double-clicked in order for it to be able to run)

• a worm does not need to be activated– it will move or copy itself to a computer

without the user’s knowledge

3

• Is a malicious program disguised in a seemingly innocent program

• Is an analogy referencing the “Trojan Horse” used by the Greeks to obtain access to the city of Troy– The Greeks were losing in the battle to overtake the

city of Troy, so their leader Odysseus, built a seemingly innocent giant wooden horse with a hollow belly, large enough for soldiers to hide in. He offered it to the Trojans as a sign of peace. The Trojans accepted the gift and celebrated their victory. Then at night while they were sleeping, the Greeks snuck out of the horse, which they were hiding in, and took the city of Troy.

4

Trojan Horse: a malicious program disguised inside of another program seemingly beneficial or harmless

• Will generally gain access to administrative areas on a computer– once it has gained access to these areas, it will

create a back door– this gives the creator of the Trojan horse

unauthorized access to the user’s computer and the information it contains

• Will sometimes monitor keystrokes and browsing activity– this information is sent to companies sending the

user content and information they did not request• Can be discreet

– meaning they do not leave any trace of their presence

5

• Became a reality in 1982 when the first virus called the “Elk Cloner” was created by Rich Skrenta– The virus created by Skrenta was created as a

prank on his friends. He modified floppy disks containing games or software which were swapped within his group of friends. Instead of running the software or game the disk displayed taunting messages.

6

• Stealth Virus: – a virus in which if anyone attempts to view an infected

sector, the virus will replace it with the clean, original version of the sector

• Boot Sector Virus:– a virus which copies itself onto a computer off of a disk

when the computer is booted up; then when someone else inserts a disk into the computer, the virus is downloaded to the new disk

7

• Are at both the state and federal level– meaning a hacker can be prosecuted at the state

level if the virus did not leave the state or at the federal level if it crossed state boundaries

• if it is prosecuted at the federal level the U.S. Secret Service will generally investigate

• Are usually considered a felony• Can be found on

http://www.ncsl.org/programs/lis/cip/viruslaws.htm– this is for individual state legislation

8

• Began in 1986 with the Computer Fraud and Abuse Act– this lays out the prosecution for using the

computer for fraud– the punishment varies depending on:

• the amount of damage caused by the worm• if the amount of damage caused was intentional

– this would be difficult to find evidence• if the worm or virus was created for commercial

advantage or personal financial gain– the punishment for such a crime is

imprisonment for up to 20 years and/or a fine

• the fine is decided by a judge9

• Against computer worms and viruses comes from anti-virus software and good judgment from the computer user– use good judgment when opening suspicious e-

mails or downloading attachments• if it really does not look important, then do not

open it• viruses in e-mails can find a user’s e-mail list

then send itself in an attachment to all of the contacts on the list

10

• May be completed by scanning all disks and files used on another computer before opening files– this is an easy feature contained in anti-virus

software• Requires users to scan attachments and downloads

from the Internet by an anti-virus software before opening them

11

• Calls for users in a computer lab to clean up or “reboot” a computer before using – this can be done with a simple action called

Disk Cleanup• it can be found by going to Start>All

Programs>Accessories>System Tools> Disk Cleanup

• this removes all potentially harmful temporary Internet files

– also be sure to log out when using a public computer

12

• Requires users to back up all important information periodically– in case a virus or worm does destroy all files

contained on a computer• Involves users to advise caution when

accepting copied software– sometimes software will be considered public

domain, where the manufacturer will give it to users at little or no cost

– be sure the copied software is from a trusted source

13

• Is the most common form of computer protection against viruses and worms

• Was first introduced in 1990• Needs to be high-quality

– there is free anti-virus software on the Internet which will not protect a user’s computer as well as a program paid for

• Needs to updated regularly – most software will update itself regularly when

connected to the Internet, be sure to install all updates possible

14

• Recommended for Windows® includes:– McAfee VirusScan®

– Norton AntiVirus®

• Recommended for Mac® includes:– McAfee Virex®

– Intego VirusBarrier®

– Norton AntiVirus®

15

• Computer Fraud and Abuse Act. (2003, January). Retrieved October 9, 2008, from Laws and Texas Tech University System Policies Affecting Computer Use: http://www.depts.ttu.edu/itts/documentation/laws/lpctexts/cfa86.html

• Economics. (2008). Retrieved October 9, 2008, from About.Com: http://kb.iu.edu/data/aehm.html

• Hacker Marks 25th Anniversary of First Computer Virus. (2007, September 6). Retrieved October 9, 2008, from FOXNews.Com: http://www.foxnews.com/story/0,2933,295813,00.html

• Kutner, T. (2007). Tips from Tonna for your PC. Retrieved October 9, 2008, from Computer Lynx: http://www.computer-lynx.com/a-virus-or-worm.htm

• Lehtinen, Rick, and G. T. Gangemi. Computer Security Basics, 2nd Edition. O'Reilly, 2006.

16

• Computer Viruses: Making the Time Fit the Crime. (1997). Retrieved October 9, 2008, from Ford Marrin Esposito Witmeyer & Gleser, L.L.P: http://www.fmew.com/archive/virus/

• Fosnock, C. (2005). Computer Worms: Past, Present, and Future. Retrieved October 9, 2008, from East Carolina University: http://www.infosecwriters.com/text_resources/pdf/Computer_Worms_Past_Present_and_Future.pdf

• Protecting your computer from viruses. (2007). Retrieved October 9, 2008, from University of Washington: http://www.washington.edu/computing/virus.html#HOW

• The History of Computer Viruses. (2008). Retrieved October 9, 2008, from Virus Scan Software: http://inventors.about.com/gi/dynamic/offsite.htm?zi=1/XJ/Ya&sdn=inventors&cdn=money&tm=10&gps=166_142_1436_695&f=10&tt=14&bt=1&bts=0&zu=http%3A//www.virus-scan-software.com/virus-scan-help/answers/the-history-of-computer-viruses.shtml

• Worms. (2007). Retrieved October 9, 2008, from Cybercrime: http://cybercrime.planetindia.net/worms.htm

17

18

Project Coordinator:

Maggie Bigham

Production Manager:

Dusty Moore

Executive Producers:

Gordon Davis, Ph.D.,

Jeff Lansdell

Production Coordinator:

Jessica House

Graphic Designer:

Ann Adams

© MMIXCEV Multimedia, Ltd.