1. Computer Viruses Standard A-4 (Safety Unit)

2. Introduction
As computer users, we are all familiar with the term computer virus
But, do we really understand how these nuisances work?

3. Background
Computer viruses became widespread in the 1980’s due to many factors
The increased usage of computers
Trojan Horse
Floppy disks
These factors set the stage for a technological petri dish for computer viruses to flourish

4. Definition
A virus is a program that reproduces itself, hides in other computer code without permission, and does nasty or undesirable things not intended by its victim.
Computer viruses are called viruses because they share some of the traits of biological viruses. Computer viruses pass from computer to computer like a biological virus passes from person to person.

5. FACTS
Computer viruses were named after their biological counterparts because of their similar traits
A virus passes from one entity to another
A virus can cause inconvenience and suffering
A virus can spread into an epidemic

6. Types of Viruses
Virus—small piece of software that piggybacks on real programs
viruses—an virus moves around in messages and usually replicates itself by automatically mailing itself to dozes of people in the victim’s address book
Worm—a small piece of software that uses computer networks and security holes to replicate itself
Trojan horse—a computer program that claims to do one thing (it may claim to be a game) but instead does damage when you run it (it may erase your hard drive)

7. Initialization
When first turned on, a computer loads an operating system or DOS into main memory from a disk
When an infected file is run, that file is loaded into main memory also
Once the file begins to execute, the virus becomes “active”

8. Reproduction
Typically, its first objective is to replicate (or reproduce)
“Virus programs, typically written in machine code, usually employ DOS commands to commandeer system resources that the virus must use.”

9. Macro Viruses Macro viruses are the most common virus today
Unlike executable viruses, macro viruses cannot infect any file
Microsoft Word documents & Excel spreadsheets
The reason is the convenient macro languages that automatically perform tasks with little to no user input
Once an infected file is opened, the virus copies itself into the global template used to store global macros

10. Evolution
Luckily, executable and boot sector viruses are declining because of CD’s
Computer technology is ever growing. Along with it, unfortunately, comes the evolution of computer viruses

11. The Computer Worm Also known as the email virus
This new virus takes advantage of the World’s growing dependency on electronic mail
The most famous is the Melissa virus of 1999
It was the fastest spreading epidemic in history

12. Code Red Worm FBI agent Dave Thomas mentioned Code Red in his speech
What is Code Red? Search the following web address or create a search for Code Red to read information about the Code Red Worm

13. No Laughing Matter
U.S. Businesses lost $5 billion to $6 billion due to computer viruses
Viruses have penetrated the computers of:
NASA
The Defense Data Network
Capitol Hill
The 2nd Circuit Court of Appeals
IBM
The White House
A British Nuclear Power Plant
The Naval Ocean Systems Command
At least 2 viruses infiltrated Allied computers in 1991 during the Gulf War

14. Discussion Questions
Why do you think someone would want to create a virus, knowing that it would harm others and their computers?
How can we prevent ourselves from becoming a victim of a computer virus?
Hard Drive: the internal storage unit for software in the computer
Computer Software: the programs that a computer uses to complete a task
(electronic mail) messages sent from one computer to another
Floppy Disk: a temporary disk which is used for storage and retrieval in a computer
Crash: this occurs when the hard drive software becomes scrambled or deleted and causes the computer to malfunction
Download: the process of acquiring a file or program from another computer
Internet: the network of phone lines, computers, and devices that connect computers worldwide
Anti-Virus Software: software application programs which will scan disks or other programs being loaded into a computer, detect a virus, and stop its spread
Cyberspace: the virtual world of digital communication

15. An Ounce of Prevention Don’t share floppy disks with anyone.
Don’t download anything from the Internet
Install anti-virus prevention software on your computer.
Never recycle floppy disks that you know once contained a virus.
Don’t download an attachment file from the Internet because it could be infected with a virus.
Hard Drive: the internal storage unit for software in the computer
Computer Software: the programs that a computer uses to complete a task
(electronic mail) messages sent from one computer to another
Floppy Disk: a temporary disk which is used for storage and retrieval in a computer
Crash: this occurs when the hard drive software becomes scrambled or deleted and causes the computer to malfunction
Download: the process of acquiring a file or program from another computer
Internet: the network of phone lines, computers, and devices that connect computers worldwide
Anti-Virus Software: software application programs which will scan disks or other programs being loaded into a computer, detect a virus, and stop its spread
Cyberspace: the virtual world of digital communication

16. An Ounce of Prevention (continued)
Never double-click on an attachment that contains an executable that arrives as an attachment.
Attachments that come in as Word Files (.DOC), spreadsheets (.XLS), images (.GIF AND .JPG), etc., are data files and they can do no damage.
A file with an extension like EXE, COM, or VBS is an executable file, and an executable file can do any sort of damage it is designed to do. Once you run it, you have given it permission to do what it was designed to do on your computer.
Hard Drive: the internal storage unit for software in the computer
Computer Software: the programs that a computer uses to complete a task
(electronic mail) messages sent from one computer to another
Floppy Disk: a temporary disk which is used for storage and retrieval in a computer
Crash: this occurs when the hard drive software becomes scrambled or deleted and causes the computer to malfunction
Download: the process of acquiring a file or program from another computer
Internet: the network of phone lines, computers, and devices that connect computers worldwide
Anti-Virus Software: software application programs which will scan disks or other programs being loaded into a computer, detect a virus, and stop its spread
Cyberspace: the virtual world of digital communication

17. Antivirus Strategy

18. Debate/Discussion
Suppose a person’s medical records were corrupted by a computer virus, and that person died because of faulty (or missing) medical information. If you were the judge and were to decide the fate of a guilty computer virus creator, what you you decide? How did you come to this conclusion?
Hard Drive: the internal storage unit for software in the computer
Computer Software: the programs that a computer uses to complete a task
(electronic mail) messages sent from one computer to another
Floppy Disk: a temporary disk which is used for storage and retrieval in a computer
Crash: this occurs when the hard drive software becomes scrambled or deleted and causes the computer to malfunction
Download: the process of acquiring a file or program from another computer
Internet: the network of phone lines, computers, and devices that connect computers worldwide
Anti-Virus Software: software application programs which will scan disks or other programs being loaded into a computer, detect a virus, and stop its spread
Cyberspace: the virtual world of digital communication

19. Popular Anti-Virus Software Program
Norton (Symantec Company)
McAfee (Network Associates Company)
Command Software Systems, Inc.

20. Sources http://www.howstuffworks.com/virus.htm
(numerous resources on computer viruses, hoaxes, antivirus software, etc.)
(virus template for PowerPoint)