Computer Science
Class-VIII
Chapter-1 The Computer Viruses
A. Answer these questions orally:
1. What do you know about virus?
Answer: Computer viruses are the software written with malicious intention of causing harm to the programs and data stored in the system.
2. What is the difference between a hacker and a cracker?
Answer: Hacker refers to the people who use their skills to enter into computer without authorization.
Cracker is a malicious programmer who gains unauthorized access to computer system for the purpose of stealing.
3. What are Trojan horse programs?
Answer: Trojan horse program is a file that appears harmless unless it has been executed.
B. Tick the correct option:
1. Relax, Melissa A and Bablas are examples of ______ viruses.
a. Logic Bomb b. Network c. Macro d. Boot Sector
Answer: Macro
2. The name _______ has been derived from Greek mythology.
a. Trojan Horse b. Worm c. Multipartite d. Stealth
Answer: Trojan horse
3. _____ is/ are the example of antivirus program.
a. Norton b. McAfee c. PC-cillin d. All are correct
Answer: All are correct
C. Name the virus:
1. Spreads by infected floppies, infecting first the boot sector of the hard disk and then the executable files.
Answer: Multipartite virus
2. Program that gets executed only when a specific condition is met.
Answer: Logic Bomb
3. Hides in the boot sector of the hard disk.
Answer: Boot sector virus
4. Spreads across networks in computers.
Answer: Network virus
5. Programs created to enter data processing programs and modify or destroy the data.
Answer: Worms
D. Give an example of each:
1. Boot sector virus
Answer: Polyboot B
2. Logic Bomb
Answer: Friday the 13th
3. People who create viruses
Answer: Hacker, Cracker
4. Antivirus programs
Answer: Norton
5. A way of protecting your computer from virus.
Answer: Install antivirus
Section-2
A. Fill in the blanks:
1. Computer viruses have the capability to ______ themselves.
Answer: Replicate
2. The virus can destroy the ______ and _________ stored in the computer system.
Answer: Files and folders
3. _____ and ________ are examples of Macro Viruses.
Answer: Relax, Melissa A
4. The ______ program disguises itself as a utility program but can destroy the data stored in the computer.
Answer: Trojan Horse
5. A virus can enter in the system through______, ___________, or ___________.
Answer: Storage device, network, internet.
B. State true or false.
1. Computer virus can spread through the air.
Answer: F
2. Boot sector virus hides in the boot sector of the hard disk.
Answer: T
3. Norton, MCAfee and PC-cillin are some popular antivirus software.
Answer: T
4. Multipartite viruses hide themselves from antivirus software by resorting to tricks.
Answer: F
5. Run Quick Scan is to scan the commonly infected areas and start-up files.
Answer: T
C. Match the following:
1. Macro virus a. Ywinz
2. Network virus b. Relax, Melissa A, Bablas
3. Logic Bomb c. Polyboot B, Anti EXE
4. Boot Sector viirus d. Nimda, SQL Slammer
5. Multipartite virus e. Friday the 13th
Answer:
1. b.
2. d.
3. e.
4. c.
5. a.
D. Differentiate between:
1. Hackers and Crackers
Answer: Hackers break into secure systems to gain knowledge.
Cracker gain unauthorized access to computer for corrupting information.
2. Network and Boot Sector Virus
Answer: Network virus spreads across network in computers.
Boot sector virus hides in the boot sector of the hard disk.
3. Trojan Horse and Worms
Answer: Trojan horse program disguises itself as a game or a utility program but when executed it can destroy the data stored in the computer.
Worms are programs which have been created to enter data processing programs and destroy or modify the data.
4. Virus and Antivirus
Answer: Virus infect and corrupt the data files.
Antivirus protect computer from viruses.
E. Answer the following questions:
1. What do you understand by computer virus? How is different from biological virus?
Answer: Computer viruses are in fact the malicious programs. Computer virus infect and corrupt computer files.
Biological viruses spreads in humans and computer viruses are programs that spreads in computer system.
2. Explain any three types of viruses.
Answer:
1. Network Virus: This kind of virus spreads across networks in computers.
2. Logic Bomb: A logic bomb is a program that gets executed only when a specific condition is met.
3. Boot Sector virus: It hides in the boot sector of the hard disk. It infect the computer disk.
3. How do the following spread from system to system.
Trojan Horse, Worms and Network virus.
Answer: Trojan horse, Network and Worms spreads from one computer to another by using networks.
4. Write some of the ways to prevent your system from the virus attack.
Answer:
Avoid the use of external or unknown discs and if required scan the disc.
Do not open unknown mails.
Never install the pirated software in your system.
Install antivirus in your computer.
Always keep a backup copy of your data files.
5. What do you understand by an antivirus software? Name some of the useful antivirus software.
Answer: Anti virus software are the utilities which prevent the viruses form entering into your system. They can also detect and remove the virus entered in your system.
Antivirus software are:
1. Norton antivirus from symantec 2. McAfee 3. PC- cillin
6. How do you start Norton antivirus to scan your system.
Answer: How to start Norton Antivirus:
1. Click start button
2. Go to Programs
3. Point on Norton Antivirus
4. Click Norton Antivirus in the cascading menu.
7. Write the steps to update virus definitions using Norton antivirus.
Answer: Steps to update virus definitions:
1. Connect to the Internet.
2. In the Symantec window, click the Run live update link.
3. A live update window is displayed.
4. Click the next button on the dialog box and follow instructions.
Wow it is really wonderful and awesome thus it is very much useful for me to understand many concepts and helped me a lot.
ReplyDeleteGenuine Experience Certificate Provider in Hyderabad
Genuine Experience Certificate Provider in Pune
Genuine Experience Certificate Provider in Bangalore
Genuine Experience Certificate Provider in Delhi