Computer Science
Class-VIII
Chapter-7 Computer Threats
A. Tick the correct answer:
1. Hardware errors frequently damage______ on new PC and disks.
a. data b. colour c. shape d. password
Answer: data
2. When a _____ is infected with a virus, the computer crashes and restarts every few minutes.
a. software b. CPU c. computer d. mouse
Answer: software
3. ______ interactions are a significant source of problems.
a. hardware b. malware c. software d. all of these
Answer: software
4. ________ can delete files, destroy data and can even prevent your computer from booting.
a. antivirus b. software c. hardware d. viruses
Answer: viruses
5. Your computer may get infected by copying infected files from CD and ______.
a. pen drives b. CPU c. modem d. internet
Answer: pen drives
6. ______ virus loads itself to the boot sector of the floppy disk.
a. polymorphic b. boot sector c. worm d. script
Answer: boot sector
7. _____ virus is written using script languages.
a. trojan b. boot c. worm d. script
Answer: script
8. A computer worm is a standalone malware computer program that replicates itself in order to spread to other____.
a. programgs b. networks c. hardwares d. computers
Answer: computers
B. Fill in the blanks:
1. When a PC or disk gets old, it might start acting_____ and damage some data before it totally.
Answer: Erratically
2. When a computer is infected with a virus you are unable to ______ files, or the contents of the files get _______.
Answer: deleted
3. _____ can affect a computer in many ways.
Answer: Virus
4. ______ is a types of mini-program that can easily infect a particular computer system.
Answer: Macro virus
5. _______ is to practise of modifying the features of a system.
Answer: Hacking
6. ______ is a type of cybercrime that is designed to trick you into disclosing valuable information.
Answer: Phishing
7. ______ is a method by which a person's authentication information is generated by digitising measurements.
Answer: Biometric
8. A _____ is a ______ device that can be a software program or a dedicated network appliance.
Answer: Firewall, Security
C. Write 'T' for true and 'F' for false:
1. A computer virus spread when you copy the infected file to some other computer.
Answer: T
2. All e-mail attachment is safe, and can be downloaded without any concerns.
Answer: F
3. Virus, worms or Trojan horses are all software that harms the computer in some or the other way.
Answer: T
4. A worm can spread on its own.
Answer: T
5. Norton is one of the type of virus software.
Answer: F
6. Antivirus software scans and detects the unwanted programs.
Answer: T
D. Answer the following questions in short.
1. Define the following terms.
(i) trojan horse (ii) worm
Answer:
i) Trojan Horse: A Trojan horse is a hacking program that is a non self replication type of malware which gains privileged access to the operating system.
ii) Worm: A computer worm is a standalone malware computer program that replicates itself in order to spread to other computer.
2. How is a network formed?
Answer: A network is formed when a group of computers are connected to one another, and can access and share information.
3. What is a script virus?
Answer: This type of virus is written using script languages. They spread and infect files by taking advantage of vulnerability ties in the microsoft windows operating systems.
4. Give five symptoms of a computer virus.
Answer:
1. You are unable to access files.
2. The computer crashes and restarts every few minutes.
3. The computer runs slower than usual.
4. Strange graphics are displayed on the monitor.
5. The programs behave erratically.
E. Answer the following questions in detail.
1. How does a computer get infected with a virus?
Answer: Virus can infect a computer in many ways.
* Computer may be infect by copying a infected file.
* Computer may be infected by network.
* Computer may be get infected through infected e-mail.
2. What is trojan horse?
Answer: A Trojan horse, is a hacking program that is a non self replicating type of malware which gains privileged access to the operating system. Trojan horses may steal information, or harm their host computer systems.
3. What is the process of phishing?
Answer: Phishing is a very specific type of cybercrime that is designed to track you into disclosing valuable information such as details about your bank account or credit cards.
The cybercriminal will try to track you into visiting their fake site by sending you an email that contains a hyperlink to the fake site. When you visit the fake website, it will ask your detail.
4. What is hardware threat?
Answer: When a PC or disk gets old, it might start acting erratically and damage some data. Hardware errors damage data on even new PCs and disks. Crashing of computers is quite a common phrase these days.
5. What is encryption?
Answer: This is a very sophisticated security measure used in scenarios where security measures are extreme. A code language is developed and transmitted to the receiver. This is called encryption. The receiver needs to know how to decipher and crack the code.
No comments:
Post a Comment