COMPUTER VIRUS
SUBMITTED BY,
ABINIYA.K.VIJAYAN
ROLL NO : 22
PHYSICAL SCIENCE

COMPUTER VIRUS
 A computer virus or computer worm is a malicious software program that can
self-replicate on computers or via computer networks – without the user being
aware that his machine has become infected.
 Because each subsequent copy of the virus can also self – replicate, infections
can spread very easily.
 All computer viruses are man made. They are loaded onto the computer
without the users knowledge and runs against his wishes. A simple virus that
can make a copy of itself over and over again is relatively easy to produce.
 Even such a simple virus is dangerous because it will quickly use all available
memory and bring the system to a halt.

 The first computer virus was called “Creeper”. It was invented in the early
1970’s. Since then, millions of viruses have been invented.
 The first known computer virus was written in 1981 by a man named Rich
Skrenta. This virus was termed as “Elk Cloner”.
 According to Webster’s Collegiate Dictionary, a computer virus is “a computer
program usually hidden within another program that produces copies of itself
and inserts them into other programs or files, and they usually perform a
malicious action (such as destroying data)”.

How does virus affect
 By downloading files from the Internet.
 Sharing music, files, or photos with other users.
 Through pen drive.
 Through e-mail attachments or spam e-mails.
 Through unprotected or poor administrator passwords.
 Visiting an infected website.
 Downloading free games, toolbars, media’s.
 Installing mainstream software applications without thoroughly reading
license agreements.

What are the symptoms that computer
might have a virus?
 Slow response and slow program execution.
 Random hard drive crashes and restarts.
 Distorted graphics and text.
 Files that have mysteriously vanished
 Extensive pop-up ads.
 Inability to open files with existing passwords.

Impact of Virus
 Disrupts the normal functionality of respective computer system.
 Disrupts system network use.
 Modifies configuration setting of the system.
 Disrupts computer network resources.
 Destructs of confidential data.
 Slow computer performance.
 Erratic computer behaviour.
 Unexplained data loss.
 Frequent computer crashes.

MALWARE
 “Malware” is short for malicious software.
 It is a type of software that could harm a computer system, interfere with
and gather a user’s data, or make the computer perform actions without the
owner’s knowledge or permission.
 “Malware” is the general term covering all the different types of threats to
your computer safety such as viruses, spyware, worms, trojans, rootkits etc.
 Malware is often used to against individuals to gain information such a
personal identification numbers or details, bank or credit card numbers and
passwords.

SPYWARE
 It is a type of malware.
 Spyware is a program that gets installed without the user’s permission.
 Spyware monitor’s the user’s activities on the internet and transmits that
information to the third party.
 It is often hidden from the user.
 On the internet it is sometimes called a spybot Or tracking software.
 Spyware is mostly used for the purposes of tracking and storing internet users
movements on the web.

How to avoid spywarer
 Read licensing agreements.
 Watch out for anti – spyware scams.
 Beware of clickable ads.
 Keep your Internet browser up to date.
 Scan your computer often.
 Be selective about what you download to your computer.

Trojan
 A Trojan or Trojan horse, in computing is any malicious computer program which
misrepresents itself as useful, routine or interesting in order to persuade a victim
to install it. The malicious activities that they perform are the following ;
 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.
 Trojans are usually used to take complete control of the computer.
 According to the type of action that they can perform on the affected computer,
they are classified as follows :
 Rootkit : To prevent malicious programs being detected.
 Trojan-Downloader : It can download and install new versions of malicious
programs onto your computer.
 Trojan- Game thief : It steals user account information from online gamers.

 Trojan-Spy : It can spy on how the user is using the computer.
 Trojan-Mailfinder : It can harvest email addresses from your computer.

Ways to overcome
 Use antivirus protection and a firewall.
 Get antispyware software.
 Always keep your antivirus protection and antispyware software up-to-date.
 Update your operating system regularly.
 Increase your browser security settings.
 Avoid questionable websites.
 Only download software from sites you trust.
 Carefully evaluate free software and file-sharing applications before downloading
them.
 Don’t open messages from unknown senders.
 Immediately delete messages you suspect to be spam.

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THANK YOU🙏