A computer virus is a program that can harm devices and files by infecting and modifying other programs with its own coding, which can spread and ultimately crash devices. Spyware secretly monitors users' activities and sends private data to third parties without consent. An anti-virus software detects and removes viruses and other malware from devices to keep them protected.

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14. What is a Computer Virus?
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.
How To Protect Your
Computer from Virus?
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

17. Spyware Definition
Spyware is loosely defined as malicious
software designed to enter your computer
device, gather data about you,. However,
malicious spywand forward it to a third-
party without your consent. Spyware can
also refer to legitimate software that
monitors your data for commercial
purposes like advertisingare is explicitly
used to profit from stolen data.
Whether legitimate or based in fraud,
spyware’s surveillance activity leaves you
open to data breaches and misuse of your
private data. Spyware also affects network
and device performance, slowing down
daily user activities.
By becoming aware of how spyware works,
you can avoid issues in enterprise and
personal use.
In this article, we’ll help you answer the
question: “what is spyware and what does
it do?

18. What Does Spyware Do?
Before we dive deeper, you’ll want to understand “what does spyware do on your computer?”
All spyware peeks into your data and all your computer activity — whether authorized or not.
However, many trusted computer services and applications use “spyware-like” tracking tools. As
such, the spyware definition is reserved mostly for malicious applications nowadays.
Malicious spyware is a type of malware specifically installed without your informed consent.
Step-by-step, spyware will take the following actions on your computer or mobile device:
Infiltrate — via an app install package, malicious website, or file attachment.
Monitor and capture data — via keystrokes, screen captures, and other tracking codes.
Send stolen data — to the spyware author, to be used directly or sold to other parties.
In short, spyware communicates personal, confidential information about you to an

19. TROJAN HORSE
A Trojan horse or Trojan is a type of
malware that is often disguised as
legitimate software. Trojans can be
employed by cyber-thieves and hackers
trying to gain access to users' systems.
Users are typically tricked by some form of
social engineering into loading and
executing Trojans on their systems. Once
activated, Trojans can enable cyber-
criminals to spy on you, steal your
sensitive data, and gain backdoor access
to your system. These actions can include:
Deleting data
Blocking data
Modifying data
Copying data
Disrupting the performance of computers
or computer networks
Unlike computer viruses and worms,
Trojans are not able to self-replicate.

21. What is an Anti-Virus?
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