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We have learnt about different types of malware. The damage caused by a virus is unexpected; it can
corrupt the system software or destroy data. So this explains what a computer virus does and how it
affects your device. Now let us learn about computer viruses in greater detail which will help us to stay
cautious and prepared in case of a virus attack!
Harms Caused by Computer Viruses
Different viruses will affect your computer in different ways.
They can crash your hard disk.
They can destroy all or some of your data.
They decrease the processing speed of the computer.
They can reduce or block the memory of the computer or hard disk.
They stop you from restarting your computer or keep on restarting your computer.
They send e-mails from your account without your knowledge.
Types of Computer Virus
There are various types of computer viruses that infect the computer in different ways. The most
commonly known categories of computer viruses are:
Program File Virus
Boot Sector Virus
Macro Virus
E-mail Virus
Let us learn about these in detail.
Program File Virus
A program file virus, also known as file-infecting virus is a type of computer virus that infects executable
files (program files such as .exe, .com, .sys, etc.) to make them unusable or damage permanently.
When an infected program file is executed, the code of the virus is also executed.
Once a virus has been executed, it remains active in the memory of the computer and can infect more
programs. Sometime, a program file virus is called file injector. The most commonly known program
file viruses are Jerusalem and Cascade.
Boot Sector Virus
A Boot sector virus is one of the most hostile types of computer viruses that infects the boot sector
or the Master Boot Record (MBR) of hard disks or floppy disks. Once a computer system is infected
by a boot sector virus, any disk connected to the computer will also be infected. The most commonly
known boot sector viruses are Michelangelo and Stoned.
Macro Virus
A macro virus is a type of computer virus that is primarily designed to infect a specific type of
documents such as Word or Excel files. If we open a macro virus infected document, the macro virus
gets active into the memory and starts infecting other documents.
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