I. Match these common types of viruses with their functions.

1. Parasitic viruses a) infect applications with built-in macros

2. Companion viruses b) utilize file system features

3. Link viruses c) modify the code of the infected file

4. Boot-sector viruses d) infect scripts of command and service files

5. Macro viruses e) create duplicate of files

6. Script viruses f) infect the boot sectors of hard drive

II. Here is a list of instructions how to avoid catching a virus, some of them are right, while the others are misleading. Mark the right instructions with a tick.

1. If you have a virus-scanner you can open any attachment even if you are not sure about its content.

2. Look out for hoaxes. There are many e-mails warning of “the most destructive virus ever”, but often these viruses don’t exist.

3. Delete any e-mail you think is infected and empty your deleted items folder.

4. You can forward any attachment to a friend without being sure it is safe. Mail filtering systems will probably delete it anyway.

5. Make sure you have a recent backup of your most important work.

6. If you think you have received an infected file, send e-mails to your friends to warn them about the threat.

7. Read the e-mail. Check that the content of the message makes sense before you open any attachment.

8. Send any e-mail you think is infected to an anti-virus company. They can tell you if it is a virus or not.

III. A little bit of statistics.

Out of approximately 61,000 malicious programs for the Microsoft Windows operating system there have been arrests and convictions of the authors of only five malicious programs:

1. the author of a worm released in 1988

2. the authors and distributors of the MBDF virus

3. the author of the Pathogen virus

4. the author of the Melissa virus

5. the author of the Anna worm

Except for the author of the Pathogen virus, each of these criminals received very light punishment.

How can you explain the fact? What are the reasons for rare arrest and prosecution and weak punishment? Who is more responsible for that: legislators, police or mass media? Complete the chart with your own ideas.

Legislators	Police	Mass Media
1. Lack of criminal statutes that effectively proscribe writing and distributing malicious programs. 2. 3.	1. Lack of money to permit an investigation of all cyber crimes. 2. 3.	1. Praising the criminal suspect by admiring his programming skills for the purpose of causing a sensation and attracting people attention. 2. 3.

IV. Study the following information.

1987 - Lehigh virus infected the COMMAND.COM file on DOS diskettes at Lehigh University. The author of the Lehigh virus was never identified, so there was no punishment for him.

1992 – MBDF virus (created at Cornell University) was released in shareware programs (computer games). The virus caused some programs to crash when the user selected an item from the menu bar. The virus took several seconds to infect each program file on the victim’s computer, and, during those several seconds, the display would freeze. If the victim rebooted the computer during those several seconds, application files on the computer could become corrupted.

1994 – Pathogen computer virus was released in the United Kingdom, by uploading an infected file to a computer bulletin board, where victims could download a copy of the file. The Pathogen virus counted the number of executable (e.g. *.EXE and *.COM) files that it infected. When the virus infected 32 files and an infected file was executed between 17:00 and 18:00 on a Monday: the keyboard was disabled; data in the first 256 cylinders of the hard disk drive are corrupted; a message appeared that include: “I’ll be back for breakfast…. Unfortunately some of your data won’t!!!!”

1. What types of viruses are mentioned above?

2. What was the source of initial release of the viruses?

3. Have the viruses become more sophisticated over the past years?

4. Find information about a recent virus and tell it to the class.

Jigsaw activities.