Quick Check

Fill in the blanks.

1. A computer virus is a program that attacks a computer and is written by programmers.
2. Trojan Horse is a coded program that masks the existence of a virus and can appear as a friendly application.
3. A program file virus infects program or executable files with extensions like .com, .exe and .sys, often causing permanent damage.
4. Spyware is designed to collect information and data on users and observe their activity without their knowledge, often collecting personal information like passwords.
5. To protect your computer from viruses, it’s important to keep your antivirus program updated and scan external storage devices before use.

Choose True or False for the following statements.

1. Antivirus programs check computer files for viruses and can remove them. True
2. An antivirus consists of a virus database and a scan engine to identify and verify infections. True
3. Antivirus software can scan incoming e-mails to detect viruses in attachments. True
4. Full system scan is typically performed when antivirus software is installed for the first time or updated. True

Time to Perform

A Fill in the blanks.

1. A disk or hard drive consists of smaller sections known as sectors.
2. Sweeper is a virus but looks like an antivirus program.
3. Antivirus programs check the files on your computer to detect the viruses and also remove them.
4. A virus database needs to be updated frequently to identify new virus programs.
5. Full System Scan scans the entire system.

B State whether the following statements are true or false.

1. Installing antivirus software does not assure a 100% protection. True
2. Virus cannot be separated from the data file. True
3. It is important to create a backup of the imported files every day. True
4. We should scan the hard disk within a week. False
5. Spyware is designed to collect information and data on users and observe their activity without their knowledge. True

C Choose the correct answer.

1. Which of the following is true for spyware?
   a. It is referred to as tracking software. ☑
   b. It tricks the user by acting as an original file.
   c. It takes advantage of security weaknesses to replicate.
   d. It creates fake malware files in the computer.
2. Stone virus is an example of ____ virus.
   a. worm
   b. program file
   c. boot sector ☑
   d. network
3. Which of the following is not true for Marburg?
   a. It appears in different forms.
   b. It changes the location of the infected file. ☑
   c. It changes binary pattern of the infected file.
   d. It infects a file.
4. ____ infects a computer in a network and then moves on to the next and the cycle keeps on repeating.
   a. Elkern
   b. Michelangelo
   c. MSBlast
   d. SQL Scanner ☑
5. Which of the following is true for Dir-2?
   a. It is designed to change the location of the infected file. ☑
   b. It enters the system through a network.
   c. It creates a copy of itself.
   d. It appears in different forms.

D Name the following.

1. Area of hard disk that stores valuable information.
   Boot Sector
2. Virus that gets activated at the time of booting.
   Boot Sector Virus
3. A virus that reports about fake viruses.
   Sweeper
4. A sign that computer has been infected by a spyware.
   Slow computer speed
5. Two main components of an antivirus.
   a. Virus database
   b. Scan engine

E Answer the following questions.

1. How does a virus enter into a computer? How can we prevent a computer from getting infected by a virus?
   A virus enters into a computer through:
   a. Infected CDs and pen drives.
   b. E-mail attachments.
   c. Files downloaded from the Internet.
   d. Infected application.
   Measures to prevent virus infection:
   a. Keeping antivirus updated.
   b. Restricting system access.
   c. Being careful with e-mail attachments.
   d. Scanning pen drives and CDs before using.
   e. Scanning hard disk every month.
   f. Backing up files every day.
   g. Installing a firewall.
2. Discuss about the common types of viruses with their examples.
   a. Boot Sector Virus: Stone virus
   b. Trojan Horse: Backdoor, Exploit
   c. Program File Virus: Sunday
   d. Polymorphic Virus: Elkern, Marburg
   e. Network Virus: SQL Scanner
   f. Directory Virus: Dir-2
3. What is malware?
   Malware refers to programs that are harmful to a computer. It includes viruses, worms, trojan horses, spywares.
4. Write a note on antivirus. Also, enlist the actions taken by an antivirus and the steps to use it.
   An antivirus is a tool used to remove viruses from our computer.
   Actions include repair (removes the virus from the infected files) and delete (the infected file is deleted along with the virus).
   Steps to use:
   a. Click the Start button
   b. Launch the antivirus program.
   c. Run the scan.
5. Why is it important to update an antivirus regularly?
   Because updating the antivirus regularly helps in identifying new viruses.

Extra Questions

1. Virus stands for Vital Information Resources Under Seize.
2. The first sector is known as boot sector.
3. Trojan Horse steals information from the computer.
4. Worm program duplicates (replicates) itself.
5. MyDoom is considered as the most expensive virus in the world.
6. Polymorphic Virus appears in different forms.
7. Directory Virus changes the location of the infected files.
8. The first computer virus for MS-DOS was a boot sector virus named Brain in the year 1986.
9. A trojan horse does not replicate. True
10. A computer virus cannot infect computer hardware or protected CDs. True
11. Kaspersky, McAfee and Quick Heal are paid antivirus software. True
12. A computer virus can only infect computer software. True
13. Name some popular antiviruses.
    Norton, Kaspersky, AVG, McAfee, Quick Heal.