A computer virus attaches itself to programs and replicates, infecting other computers. There are several types of viruses including boot sector viruses that infect boot sectors and run before operating systems load, encrypted viruses that use encryption to avoid detection, file viruses that append to files, and email viruses spread through email. Viruses can harm data, slow systems, and log keystrokes. Common signs of viruses are frequent pop-ups, slowdowns, changed homepages, corrupted files, and password changes. Viruses can be removed using antivirus software or manually.

1. BY:G.DHANUSHIA

2. DEFINATION OF COMPUTER VIRUS
 A computer virus is a sort of malware that attaches itself to another
program and can replicate and propagate once it has been installed on a
user’s computer. When a computer changes the way in which it should
work normally, it is said to be infected by a virus. This virus may spread
from one computer to another.

3. TYPES OF COMPUTER VIRUS

4. BOOT SECTOR VIRUS
 This virus infects the boot sector of the
computer and runs every time the
computer boots and before the
operating system loads. Floppy
disks and other bootable media become
infected. They are sometimes referred to
as memory viruses because they do not
infect the file system.

5. ENCRYPTEDVIRUS
 To avoid detection by
antivirus software, this
type of virus is encrypted.
There’s also a decryption
algorithm included. As a
result, before running, the
virus decrypts.

6. FILE VIRUS
 Infects the system by appending
itself to the end of a file. It
changes the start of a program
such that the control jumps to its
code.

7. EMAIL-VIRUS
 They are comprised of malicious code
that is propagated through email
messages and can be activated when a
user clicks on a link in an email
message, opens an email attachment, or
interacts in any manner with the infected
email message.

8. WHAT DOES A COMPUTER VIRUS DO?
 A virus can harm or destroy data, slow down system resources, and log
keystrokes, among other things.
 A virus has the ability to have unexpected or harmful outcomes during this
procedure, such as destroying system software by corrupting data.
 Some computer viruses are designed to damage your computer by destroying
files, corrupting applications, or reformatting the hard drive. Even less dangerous
computer infections can have a substantial impact on your system’s performance,
eating up RAM and triggering frequent crashes. Other viruses may just clone
themselves or flood a network with traffic, rendering all internet activity difficult.

9. COMMON SIGNS OF COMPUTER
VIRUES
 Opening of Pop-up window frequently. Pop-ups may entice you
to visit odd locations. They will take you to a page to download
any antivirus (which is actually not an antivirus), or other harmful
software.
 Slowing down of system without any reason.
 Updated homepage. For example, the homepage is replaced by
a website and you would not be able to undo that replacement.
 Identifying that your files are corrupted.
 Unknown change in the password that does not let you login.

10. HOW TO REMOVE COMPUTER VIRUSES
To get rid of a computer infection, you
have two options:
• Do-it-yourself manual approach
• Seek the assistance of a reliable
antivirus product
.

11. ANTIVIRUS
 Antivirus software is a program that searches for, detects, prevents,
and removes software infections that can harm your computer.
 Antivirus can also detect and remove other dangerous software
such as worms, adware, and other dangers.
 This software is intended to be used as a preventative measure
against cyber dangers, keeping them from entering your computer
and causing problems.