Computer Virus and its Types

A computer virus is a kind of malicious computer program, which when executed, replicates itself and inserts its own code. When the replication is done, this code infects the other files and program present on your system. 

These computer viruses are present in various types and each of them can infect a device in a different manner. 

In this article, we shall discuss in detail what is a computer virus and what are its different types. Also, we will read on to know what is an Anti-virus and how it can nullify a virus in our computer devices, along with some sample questions from the competitive exam point of view. 

To know more about the Fundamentals of Computer, visit the linked article. 

Apart from being aware of what a computer virus is, this topic is even important for candidates preparing for Government exams. Major competitive exams in the country comprise Computer Knowledge as an integral part of the syllabus and questions based on virus and anti-virus can also be expected in these exams. 

Thus, to excel in the upcoming Govt exams, aspirants must go through this article in detail and carefully study the different types of viruses.

A computer virus is a program which can harm our device and files and infect them for no further use. When a virus program is executed, it replicates itself by modifying other computer programs and instead enters its own coding. This code infects a file or program and if it spreads massively, it may ultimately result in crashing of the device. 

Across the world, Computer viruses are a great issue of concern as they can cause billions of dollars’ worth harm to the economy each year. 

Since the computer virus only hits the programming of the device, it is not visible. But there are certain indications which can help you analyse that a device is virus-hit. Given below are such signs which may help you identify computer viruses:

• Speed of the System – In case a virus is completely executed into your device, the time taken to open applications may become longer and the entire system processing may start working slowly
• Pop-up Windows – One may start getting too many pop up windows on their screen which may be virus affected and harm the device even more
• Self Execution of Programs – Files or applications may start opening in the background of the system by themselves and you may not even know about them
• Log out from Accounts – In case of a virus attack, the probability of accounts getting hacked increase and password protected sites may also get hacked and you might get logged out from all of them
• Crashing of the Device – In most cases, if the virus spreads in maximum files and programs, there are chances that the entire device may crash and stop working

The first thing which you might notice in case of virus attack is the speed with which your system shall process. And then gradually other changes can also be observed. 

Discussed below are the different types of computer viruses:

• Boot Sector Virus – It is a type of virus that infects the boot sector of floppy disks or the Master Boot Record (MBR) of hard disks. The Boot sector comprises all the files which are required to start the Operating system of the computer. The virus either overwrites the existing program or copies itself to another part of the disk.
• Direct Action Virus – When a virus attaches itself directly to a .exe or .com file and enters the device while its execution is called a Direct Action Virus. If it gets installed in the memory, it keeps itself hidden. It is also known as Non-Resident Virus.
• Resident Virus – A virus which saves itself in the memory of the computer and then infects other files and programs when its originating program is no longer working. This virus can easily infect other files because it is hidden in the memory and is hard to be removed from the system.
• Multipartite Virus – A virus which can attack both, the boot sector and the executable files of an already infected computer is called a multipartite virus. If a multipartite virus attacks your system, you are at risk of cyber threat.
• Overwrite Virus – One of the most harmful viruses, the overwrite virus can completely remove the existing program and replace it with the malicious code by overwriting it. Gradually it can completely replace the host’s programming code with the harmful code.
• Polymorphic Virus – Spread through spam and infected websites, the polymorphic virus are file infectors which are complex and are tough to detect. They create a modified or morphed version of the existing program and infect the system and retain the original code.
• File Infector Virus – As the name suggests, it first infects a single file and then later spreads itself to other executable files and programs. The main source of this virus are games and word processors.
• Spacefiller Virus – It is a rare type of virus which fills in the empty spaces of a file with viruses. It is known as cavity virus. It will neither affect the size of the file nor can be detected easily.
• Macro Virus – A virus written in the same macro language as used in the software program and infects the computer if a word processor file is opened. Mainly the source of such viruses is via emails.

Government exam aspirants can check the links given below for the detailed section-wise syllabus for the other subjects apart from Computer Awareness:

The most suitable way of making your computer virus-free is by installing an Anti-virus software. Such software help in removing the viruses from the device and can be installed in a computer via two means:

• Online download
• Buying an Anti-virus software and installing it

Further below, we bring to you details as to what anti-virus is and what are its different types along with a few examples.

Moving further, candidates can also refer to the following links to learn more about Computer Knowledge and prepare themselves accordingly:

• Difference Between RAM and ROM
• Difference Between MS Excel and MS Word
• Difference Between IPV4 and IPV 6
• Difference Between Firewall and Antivirus
• Difference Between WWW and Internet
• Difference Between Notepad and WordPad
• Difference Between Virus and Malware

An anti-virus is a software which comprises programs or set of programs which can detect and remove all the harmful and malicious software from your device. This anti-virus software is designed in a manner that they can search through the files in a computer and determine the files which are heavy or mildly infected by a virus. 

Given below is a list of few of the major antivirus software which is most commonly used:

• Norton Antivirus
• F-Secure Antivirus
• Kaspersky Antivirus
• AVAST Antivirus
• Comodo Antivirus
• McAfee Antivirus

These are few of the many anti-virus software widely used to remove viruses from a device. 

As discussed above, Computer Awareness is a common topic for major Government exams and questions based on Computer Virus and Antivirus may also be asked in the exam.

Thus, given below are a few sample computer virus questions and answers for the assistance of aspirants. 

Q 1. Which of the following is not a type of computer virus?

1. Polymorphic virus
2. Space filler virus
3. Multipartite virus
4. Trojan
5. Boot sector virus

Answer: (4) Trojan

Q 2. Which of these was the first computer virus?

1. Creeper
2. Brain
3. Worm
4. Crypto Locker
5. Morris Worm

Answer: (1) Creeper

Solution: Creeper was the first-ever computer virus and was an experimental self-replicating virus released in the year 1971.

Q 3. Which of the following is not a source of the virus entering your system?

1. USB drive
2. Email
3. Hard Disk
4. All of the above
5. None of the above

Answer: (5) All of the above

Q 4. The other name for Non-Resident virus is _________

1. Direct Action Virus
2. Boot Sector Virus
3. Multipartite Virus
4. Overwrite Virus
5. Polymorphic Virus

Answer: (1) Direct Action Virus

Q 5. Which of the following viruses is also known as “Cavity Virus”?

1. Multipartite Virus
2. Space Filler Virus
3. Overwrite Virus
4. Direct Action Virus
5. None of the above

Answer: (2) Space Filler Virus

For more questions to ace the upcoming competitive exams, aspirants can visit the articles given below:

• Free Online Government Exam Quiz
• Free Online Mock Test Series with Solutions
• Previous Year Govt Exam Question Papers PDF with Solutions

Also, to get the best Preparation Strategy for Competitive exams, candidates can visit the linked article. 

Get the latest exam information and study material at BYJU’S and keep yourself updated.