VIII. Which words in the text have the same meaning as:

environment, mean, apply, attach, wait for, cable, zone, information, firm, some, specify, occupy, limits.

IX. What do the following abbreviations stand for?

NIC, ARPA, ARPANET, WAN, MAN, PAN, VPN, CAN, SAN, GAN, SLA.

X. Imagine that you are going to take part in a scientific conference. The theme of your report is:

1. Ukrainian Internet providers.

2. Network architectures.

Unit 6. Computer viruses

I. Read the following words and word combinations:

executable, reproduce, environment, goal, encrypt, engine, infect, achieve, via, vulnerabilities, exploit, sequence, spyware, backdoors, key loggers, bank account, self-replicating, two-dimensional model, activate, content, malware, spam, penetrate, applet, intervention, resident program, appear, processor, resident, purely.

II. Before you read the text try to answer these questions:

1. What is a computer virus?

2. What is the difference between computer virus and biological virus?

3. Who creates computer viruses?

III. Read and translate the following text. Computer viruses

Computer virus is an executable code that is able to reproduce itself. It moves from one computer to another and damages the computer’s memory or other parts of the machine. Some viruses are difficult to stop; they can damage millions of computers in a very short period of time. Viruses are an area of pure programming that carry intellectual functions on protection from being found and destroyed. Viruses seem to be the only alive organisms in the computer environment and their main goal is to survive. That is why they may have complex encrypting/decrypting engines in order to carry out processes of duplication and adaptation.

In addition, viruses can damage or completely destroy operating system, data and files that are controlled by the user. Viruses spread by introducing themselves into the executable code of other programs to infect them and corrupt data. Such copies of the virus do not get control because the information is not used as the processor instructions.

Some time later, attackers have created viruses that exploit vulnerability in popular software, such as Adobe Photoshop or Internet Explorer. Viruses spread through the introduction of the data sequence (pictures, texts) of a special code that uses the vulnerability of software.

The first virus appeared in 1986. It was called Brain. In 1987, a more dangerous virus called Jerusalem appeared. This virus stayed in a computer and did nothing until the date was Friday the 13^th; then it started to damage the computer’s memory. By the late 1990s, most computers were part of the e-mail and Internet systems. In 1999, the Melissa virus appeared. It could move from one computer to another by e-mail. A year later, the most successful virus in history reached millions of computers in less than 24 hours. When it appeared on a computer, it automatically sent itself to every other e-mail address in the computer. This virus was called I Love You. The person who made this virus was probably a very clever 23-year-old computer student from the Philippines called Onel de Guzman. He has never said that he wrote it, but detectives knew that the virus came from his computer. Onel de Guzman was not punished for his crime because in May 2000 the Philippines did not have any laws against computer crime.

Today, there are many types of viruses, which are different according to the method of distribution and functionality. Originally, viruses were distributed on floppy disks and other types of media, but now they mostly spread via the Internet. The functionality of viruses is constantly increasing and now they appear in different forms: rootkits, backdoors, key loggers, spyware and botnets.

The basis of mechanisms theory was proposed by John von Neumann, who represented a method for creating self-replicating mechanisms in 1951. The first work (written by L.S. Penrose and R. Penrose) dedicated to the creation of self-replicating system was published in the journal Nature in 1957. In this work, along with the examples of purely mechanical designs a kind of two-dimensional model of structures was proposed. Later, F. G. Stahl created the biocybernetical model of virus on the computer IBM 650 using self-replicating mechanisms method. For the first time in relation to the program word «virus» was used by Gregory Benford in the short story «The man in scars», published in the journal in May 1970. At present, there is no system for virus classification, but we can admit several types of viruses and some of them will be discussed below.

Overwriting viruses record their body instead of the program code without changing the name of the executable file so that the original program stops running.

Companion viruses, like overwriting viruses, create copies of themselves, but they do not destroy the original file. When you run the virus code executed for the first time the control is passed to the original program.

File worms create copies of themselves which are attached to the user’s name (for example, Game.exe, install.exe).

Parasitic viruses change the content of the file by adding their code. The code can be implemented at the beginning, middle or end of the program and executed before, after or in simultaneously with the program.

Viruses can penetrate your computer system in different ways. Some of them are mentioned below.

Diskettes were the most common way of infection in 1980-1990. Nowadays diskettes are substituted by modern storage devices and most modern computers are not equipped by floppy drives.

USB-flash drives replaced floppy disks and repeated their fate. A large number of viruses spread via removable storage devices, including digital cameras, digital music players (MP3-players) and mobile phones. USB-flash drives are the main source of computers infection.

Now e-mail is one of the major ways of spreading viruses. Typically viruses in an e-mail are disguised as harmless attachments: images, documents, music.

Web pages can also contain viruses because of the presence on the World Wide Web various «active» content: scripts, ActiveX-components, Java-applets. Surfing some web pages you can meet worms - viruses that penetrate the victim machine without user intervention. Worms use the so-called vulnerabilities in operating systems to access your PC. Then attackers may use the infected user's computer to send spam.

To protect any computer system a user can install an anti-virus program. The first anti-virus tools appeared in 1984. Andy Hopkins wrote a program CHK4BOMB which allowed to analyze the text file and track of all the text messages and «suspicious» parts of code. Because of its simplicity (there was used only contextual search) and effectiveness CHK4BOMB received considerable popularity. In 1985, Gee Wong wrote a program DPROTECT – a resident program that intercepted attempts to write onto the floppy and hard disks. Today there are a lot of anti-virus programs, the most popular among them being NOD 32, Kasperskiy anti-virus program, AVG, Zillya, Avast etc.

IV. Answer the following questions:

1. When did the first computer virus appear?

2. What is the main goal of computer viruses?

3. What does «vulnerability» mean?

4. How can viruses penetrate your computer system?

5. What is a spyware?

6. What was the most common way of infecting a computer in 1980-1990?

7. Is there any classification of viruses?

8. What modern anti-virus programs do you know?

V. Decide whether the following statements are true or false. It they are false, correct them.

1. The basis of mechanisms theory was proposed by Charles Johnson.

2. A program DPROTECT was created in 1985.

3. The first anti-virus tools have appeared in 1948.

4. Program CHK4BOMB was written by John von Neumann.

5. Viruses can damage or completely destroy all the files and data that are controlled by the user.

VI. Translate the following word-combinations from Ukrainian into English:

можуть пошкодити; головна мета вірусів – вижити; послідовність даних; за малий проміжок часу; не був покараний за злочин; приєднався до ім’я користувача; виконаний вперше; одночасно; розповсюдження вірусів; без втручання користувача; завдяки його простоті та ефективності; заміщувати.

VII. Find in the text words opposite to the following ones:

end, create, penetrate, this, few, long, with, begin, different, before, less, receive.

VIII. Complete the following sentences with the words from the list below:

a)infected b)classification c)record d)corrupt e)vulnerabilities f)spreading g)by h)protect i)executable.

1. Computer virus is an __________ code that is able to reproduce itself.

2. E-mail is one of the major ways of ____________ viruses.

3. Some viruses can infect only the program and ____________ data but do not change anything.

4. Then attackers may use the ____________ user's computer to send spam.

5. To __________ a computer system user can install antivirus program.

6. At present, there is no system for virus ____________.

7. Overwriting viruses ___________ its body instead of the program code.

8. ___________ are used by worms to access your PC.

9. Floppy disks were replaced ___________ USB-flash drives.