Computer Virus

1)     What is computer virus?
Ans: Computer virus is a type of computer program which is written by the programmer with the intent of destroying or damaging the data and programs residing in the computer system.

2)     Write down the purpose of creating computer virus.
Ans: The purpose of creating computer virus are:
i) To stop computer piracy
ii) To entertain user by displaying interesting message and pictures
iii) To destroy data, information and files
iv) To expose the programmers ability
v) To earn money

3)     How does a computer virus spread from one computer to another?
Ans: A virus spreads from one computer to another by:
i) Sharing infected internal portable disk like floppy disk, pen drive, CDs, etc.
ii) Opening a virus infected email, messages and attached files
iii) Downloading files and programs form the websites which are not secure
iv) Exchanging data and information over a network

4)     What are the symptoms of computer virus?
Ans: The symptoms of computer virus are:
i) Program takes long time to load.
ii) The floppy disk or hard disk is suddenly accessed without a logical reason.
iii) Increased use of disk space and growth in file size.
iv) Corrupting the system’s data.
v) Renaming all the files with different names.

5)     Write down the effects of computer virus.
Ans: The effects of computer virus are:
i) Virus can change the contents of file, and codes of program.
ii) Degrade the overall performance of computer system.
iii) Change in size of file by adding or removing text accordingly.

6)     Write some preventive ways to protect computer system form virus.
Ans: Some preventive measures are:
i) Write protect your floppy disks when using them on other computers.
ii) Scan the mail or unknown files of internet before opening in your computers.
iii) Use a good antivirus program to scan floppy disk, CD, etc. before copying.
iv) Do not install pirated software, especially computer games.
v) Do not interchange the internal disks among the computers.
vi) Do not use free distributed software.

7)     Write down the types of viruses.
Ans: The types of viruses are:
i) Boot sector virus
ii) File infector virus
iii) Multipartite virus
iv) Stealth virus
v) Macro virus

8)     What is antivirus software?
Ans: Antivirus software is software designed to detect and remove virus from computer system to ensure virus free environment.

9)     Write down any four examples of virus.
Ans: Any four examples of viruses are:
i) Disk killer                      ii) Flip             iii) Frodo        iv) Word concept

10) Write any four examples of antivirus software.
Ans: Four examples of antivirus software are:
i) Kaspersky                       ii) NOD32       iii) Norton antivirus   iv) McAfee

11) What is boot sector virus?
Ans: The virus which destroys or infects the boot sector of the disk where master boot record is stored is called boot sector virus. Eg. Danish Boot, Devel 941, Disk Killer etc.

12) How can boot sector virus harm a PC?
Ans: The boot sector virus modifies the Master Boot Record (MBR) that prevents the computer system from being able to boot or start up the computer from system disk.

13) What is program or file virus?
Ans: The virus that infects the application program is called program virus. Eg. Acid Rain, Alien.298, Crazy A etc.

14) What is stealth virus?
Ans: The most dangerous types of virus which rarely gives the information about its presence in the computer system which generally infects program files and boot records is called stealth virus. Eg. Frodo, Joshi, Whale etc.

15) What is multipartite virus?
Ans: The virus which infects both application programs and the boot sector of a disk is called multipartite virus. Eg. Invader, Flip, Tequila dtc.

16) What is Macro virus?
Ans: The virus that infects the software document or template created using word processing or spread sheet software is called macro virus. Eg. DMV, Nuclear and Word Concept etc.

17) What is Master Boot Record (MBR)?
Ans: MBR is a small program which is responsible for booting computer system.

18) What is computer worm?
Ans: A computer worm is a standalone malware computer program that replicates itself in order to spread to other computers.

19) What is Trojan horse?
Ans: A Trojan horse is a program that appears harmless, but is, in fact, malicious.

20) What is cyber spying? How it works?
Ans: Cyber spying is the act or practice of obtaining secret information without the permission of the user. It works through the Internet, networks or individual computers through the use of cracking techniques and malicious software including Trojan horse and spyware.

21) What is cyberwarefare?
Ans: Cyberwarefare refers to politically motivate hacking to conduct damage and spying to others.

22) What is adware? Explain.
Ans: Adware is a software package which automatically extracts advertisements in order to generate revenue for its author. It is usually seen by the developer as a way to recover development costs. It may allow the software to be provided to the user for free of charge.

23) What is spyware? Explain.
Ans: Spyware is software that gathers information about a person or organization without their knowledge or permission. It is mostly used for the purposes such as tracking Internet user on the web, spying on certain organization or persons and serving up pop-up ads to Internet users.

24) Write down the common characteristics of computer virus?
Ans: Common characteristics of computer virus are:
i. Replicate and spread on the others files.
ii. Destroy data, information, files or programs of a file.
iii. Steal important data and information.
iv. Load and run unwanted applications.
v. Display the unnecessary messages or pictures.
vi. Cripple the operating system of a computer.
vii. Degrade overall performance of the computer system.