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Harms Caused by Computer Viruses
07 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.
Prime (Ver. 2.2)-VII • They can reduce or block the memory of the computer or hard disk. COMPUTER VIRUS
• They stop you from restarting your computer or keep on restarting your computer.
• They can 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
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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 other programs. Sometimes, 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 which 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.

