Computer virus

Rabia Bibi 111/7/2013

Rabia bibi11777

COMPUTER VIRUSES

11/7/2013 2

Computer virus:Is a type of malware, designed to replicate itself by copying itself into the other programs stored in a computer. It may cause a program to operate incorrectly or corrupting a computer's memory.

11/7/2013 3Rabia Bibi


Malware:Software that is written and distributed for malicious purposes, such as impairing or destroying computer systems.

Characteristics of computer virusesThey are a piece of program or code.

Executes without any permission or informing to user.

Replicates, and made copies of themselves to spread.

Some types require special command to replicate.

can corrupt and distribute personal info of the user over internet.

They are all men made.


Symptoms: •Computer functions slower than normal

•Responds slowly and freezes often.

•Often restarts itself.

•See uncommon error messages, distorted menus, and dialog boxes.

•Notice applications fail to work correctly.

•Fail to print correctly.


Sundus mukhtar11800

History of computer virus


1949,

john von Neumann came up with the theory about self-replicating programs and “creeper” was the first Virus invented for experimental purpose. 1981

Apple Viruses 1, 2, and 3 are some of the first viruses in the public domain. Found on the Apple II operating system, the viruses spread through computer games.

1983

Fred Cohen, defines a computer virus as “a computer program that can affect other computer programs by modifying them in such a way as to include a (possibly evolved) copy of itself.”

04/11/2023 7Sundus mukhtar


1986,

1998,

the first PC virus, codename “The Brain” is released from Pakistan.

. StrangeBrew is the first virus to infect Java files.

The Chernobyl virus spreads quickly via .exe files

the virus is quite destructive, attacking not only files but also a certain chip within infected computers.

2000

Tristate is the first multi-program macro virus; it infects Word, Excel, and PowerPoint files.

“I Love You” virus appears. It managed to infect millions of computers in just under a day.



2001

the Code Red virus posed a serious threat to the White House website. It infected tens of thousands of computers

The same year, the Nimda virus hits the Internet. In the brief history of computer viruses this is one of the most sophisticated viruses ever to appear.

2005

March saw the world's first cell phone virus: Commwarrior-A. The virus probably originated in Russia, and it spread via text message.

2010

Stuxnet is a computer worm targeting Siemens industrial software through Microsoft Windows.



TYPES OF COMPUTER VIRUSES

BY BUSHRA KHANROLL NO: 11742

10ROLL NO: 11742

Bushra Khan 1111/7/2013

TYPES OF COMPUTER VIRUSES

Email virus Worms Trojan horses Macro virus Logic and time bomb virus Boot sector

11BUSHRA KHAN

ROLL NO: 11742

04/11/2023 Rabia Bibi 12

Email viruses

• Email viruses first started showing up in the 1990s when the use of email became widespread.

• Email virus is of two types:• Melissa virus• ILOVEYOU virus

12BUSHRA KHAN

ROLL NO: 11742


MELISSA VIRUS

• One of the most impressive viruses to hit computers was the Melissa virus, which

happened in March 1999.

13BUSHRA KHAN

ROLL NO: 11742


ILOVEYOU virus

• Another notable email virus was called the ILOVEYOU virus, which infected computers on May 4, 2000.

14BUSHRA KHAN

ROLL NO: 11742


Worms

• A program that makes copies of itself; for example, from one disk drive to another, or

by copying itself using email or another transport mechanism.

15BUSHRA KHAN

ROLL NO: 11742


Types of worms

Email WormsInstant Messaging WormsFile-sharing Networks Worms

16BUSHRA KHAN

ROLL NO: 11742


Types of COMPUTER VIRUSES

• BOOT SECTOR VIRUS• LOGIC BOMB VIRUS

ANAM HASSAN11736


Definition

A sector on the computer floppy disk drive, hard drive, or other bootable disk drive that contains instructs the computer on how to boot from the drive.

There are two kinds of boot sectors - volume boot records and master boot records.

IBM PC disk drives:

IBM PC disk drive have different types of boot sectors• MBR (master boot record) which is the first sector of a portioned hard drive

volume boot record.• VBR (volume boot record) which contains partition information at the beginning

of each partition.

04/11/2023 11:41 PM

18Anam hassan

Boot Sector


Continue

04/11/2023 11:41 PM

Anam hassan 19

Example with the help of diagram: In this example, the drive has two partitions; each partition contains its own VBR. When BIOS hands control over to the boot sectors, the MBR takes control and starts the boot process and refers to the VBR to point it to the partition information. Several major kinds of boot sectors could be encountered on IBM PC compatible hard disks, floppy disks and similar storage device.


A boot sector virus is a computer virus that infects a storage device's MBR. It is not mandatory that a boot sector virus successfully boot the victim's PC to infect it. As a result, even non-bootable media can trigger the spread of boot sector viruses. These viruses copy their infected code either to the floppy disk's boot sector or to the hard disk's partition table. During start-up, the virus gets loaded to the computer's memory. As soon as the virus is saved to the memory, it infects the non-infected disks used by the system.

The propagation of boot sector viruses has become very rare since the decline of floppy disks.

04/11/2023 11:41 PM

20Anam hassan

What does Boot Sector Virus mean?


Boot Sector VirusHOW IT WORKS:

04/11/2023 11:41 PM

21Anam hassan


LOGIC BOMB

A logic bomb also calledbecause all that's left after it detonates is computer slag, is not the same thing as a virus, although it often behaves in a similar manner. WORKING: It is a piece of computer code that executes a malicious task, such as:•Clearing a hard drive•Deleting specific files It's secretly inserted into the code of a computer's existing software, where it lies dormant until that event occurs. This event can be eitherPositive eventNegative event

SLAG CODE

04/11/2023 11:41 PM

22Anam hassan

Rabia Bibi 2311/7/201304/11/2023 22

SPEAKER:AMMARA FAROOQUI11736

Rabia Bibi 2511/7/201304/11/2023 25

TROJAN HORSES VIRUS• normal computer programs• pretends to be a regular downloadable program• incapable of replicating

Ammara farooqui

Rabia Bibi 2611/7/201304/11/2023 26

CONT.most insidious types is that the program claims to rid your computer of viruses but instead introduces viruses onto your computer.

Ammara farooqui

Rabia Bibi 2711/7/20132704/11/2023 Ammara farooqui


MACRO VIRUSES• written in a macro language• spread as an e-mail virus• depends on the application rather than the operating system

04/11/2023 28Ammara farooqui

Rabia Bibi 2911/7/201304/11/2023 29

CONT..• "infects" a Microsoft Word or similar application• causes a sequence of actions to be performed automatically

Ammara farooqui

30

HOW VIRUS ATTACKS THE SYSTEM

SPEAKER: MADIHA AHMEDROLL NO: 11761

11/7/2013 MADIHA AHMED


HOW VIRUS ATTACKS THE SYSTEM

Virus Entrance

Attachment Of Virus

Appearance Of Virus

Execution Or Running Of Effected Program

Computer System Get Effected With Virus

11/7/2013 31MADIHA AHMED


ENTRANCE

There are literally dozens of ways for viruses to enter into the computer system.



ATTACHMENT OF VIRUS

Virus attaches to its target file or software present in computer system .



APPEARANCE OF VIRUS:It can appear in the form of code, scripts, active content, other software and email attachments.



EXECUTION OR RUNNING OF PROGRAM

REPLICATION



COMPUTER IS INFECTED WITH VIRUS


Rabia Bibi 3711/7/2013 7/11/2013Noor-ul-ainn 37

Anti virusnoor-ul-ainn

roll no:

11 77

3

Noor-ul-ainn7/11/2013

11/7/2013 Rabia Bibi 38

Definition:•

“Antivirus" is protective software designed to defend your computer against malicious software. Malicious software, or "malware" includes: viruses, Trojans, key loggers, hijackers, dialers, and other code that vandalizes or steals your computer contents. In order to be an effective defense, your antivirus software needs to run in the background at all times.

7/11/20Noor-ul-ainn 38

PROTECT

7/11/2013


Problems:• One of the most common

reasons for failures or problems in computers is the lack of antivirus software, or expired antivirus software.

• A few examples are provided below:

• Computer run slowly itself.• Damage parts of the system or

how the system operates without the owner's knowledge .

• Be used to steal personal details .

• receiving out unauthorized messages / emails.7/11/2013 Noor-ul-ainn 39


anti-virus:HOW IT WORKS ?

• Anti virus software will constantly monitor the activity of all the programs.

• If any program tries to write data on an executable file the antivirus software will flag the program having a suspicious behavior means the suspected programs will be marked as virus.

7/11/2013 Noor-ul-ainn 40


So What Does Antivirus Software Do?

• Antivirus software is the "policeman" at the gate of a computer system. It protects the computer from incoming threats and seeks out, destroys and warns of possible threats to the system.



Cont.. New viruses are coming

out all the time. It is the job of the antivirus software to keep up with the latest threats. This is achieved by daily updates of the antivirus data base,its purpose is to counteract the latest threats to provide constant protection.



Examples:• Examples of common antivirus

programs include Norton Antivirus, Kaspersky Anti-Virus, and ZoneAlarm Antivirus.

7/11/2013

slide 7

43antivirus

Rabia Bibi 4411/7/2013 11/07/2013Hira Arshad44

Preventive measures for

computer virus

Rabia Bibi 4511/7/2013 11/07/2013Hira Arshad

VIRUS PROTECTION SOFTWARE

45


ANTIVIRUS PROGRAM

46


ANTI –SPAY WARE

47


AVOID DANGEROUSWEBSITES

48


SCANNING ATTACHMENTS

49


http://www.makeuseof.com/tag/history-computer-viruses-worst-today-case-wondering/ http://inventors.about.com/od/computerviruses/http://www.howstuffworks.com/virus2.htm

www.buzzle.com/articles/different-types-of-computer-viruses.html

http://www.computervirusremovalguide.com/a-brief-look-at-the-history-of-computer-viruses.phpwww.makeuseof.com/tag/types-computer-viruses-watch/www.webopedia.com/TERM/V/virus.html/

Computer virus

Education

Transcript of Computer virus