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Computer virus

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a brief introduction about computer viruses, their types, how they spread and what precautions should be followed to stay unaffected.

a brief introduction about computer viruses, their types, how they spread and what precautions should be followed to stay unaffected.

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  • 1. 11/7/2013 Rabia Bibi 1
  • 2. COMPUTER VIRUSES 11/7/2013 Rabia bibi 11777 2
  • 3. 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 Rabia Bibi 3
  • 4. Malware: Software that is written and distributed for malicious purposes, such as impairing or destroying computer systems. Characteristics of computer viruses They 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. 11/7/2013 Rabia Bibi 4
  • 5. 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. 11/7/2013 Rabia Bibi 5
  • 6. History of computer virus Sundus mukhtar 11800 11/7/2013 Rabia Bibi 6
  • 7. 1949, john von Neumann came up with the theory about selfreplicating 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.” 1/29/2014 11/7/2013 Rabia Bibi Sundus mukhtar 7
  • 8. 1986, the first PC virus, codename “The Brain” is released from Pakistan. . StrangeBrew is the first virus to infect Java files. 1998, 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. Tristate is the first multi-program macro virus; it infects Word, Excel, and PowerPoint files. 2000 “I Love You” virus appears. It managed to infect millions of computers in just under a day. 1/29/2014 11/7/2013 Rabia Bibi Sundus mukhtar 8
  • 9. 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. 1/29/2014 11/7/2013 Rabia Bibi Sundus mukhtar 9
  • 10. 11/7/2013 ROLL NO: 11742 Rabia Bibi 10
  • 11. TYPES OF COMPUTER VIRUSES  Email virus  Worms  Trojan horses  Macro virus  Logic and time bomb virus  Boot sector 11/7/2013 BUSHRA KHAN Bushra Khan ROLL NO: 11742 11
  • 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 1/29/2014 BUSHRA KHAN Rabia Bibi ROLL NO: 11742 12
  • 13. MELISSA VIRUS • One of the most impressive viruses to hit computers was the Melissa virus, which happened in March 1999. 11/7/2013 BUSHRA KHAN Rabia Bibi ROLL NO: 11742 13
  • 14. ILOVEYOU virus • Another notable email virus was called the ILOVEYOU virus, which infected computers on May 4, 2000. 11/7/2013 BUSHRA KHAN Rabia Bibi ROLL NO: 11742 14
  • 15. 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. 11/7/2013 BUSHRA KHAN Rabia Bibi ROLL NO: 11742 15
  • 16. Types of worms Email Worms Instant Messaging Worms File-sharing Networks Worms 11/7/2013 BUSHRA KHAN Rabia Bibi ROLL NO: 11742 16
  • 17. • BOOT SECTOR VIRUS • LOGIC BOMB VIRUS 11/7/2013 Rabia Bibi 17
  • 18. 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. 1/29/2014 1:35 11/7/2013 AM Rabia Bibi Anam hassan 18
  • 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. 1/29/2014 1:35 11/7/2013 AM Rabia Bibi Anam hassan 19
  • 20. What does Boot Sector Virus mean? 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 nonbootable 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. 1/29/2014 1:35 11/7/2013 AM Rabia Bibi Anam hassan 20
  • 21. 1/29/2014 1:35 11/7/2013 AM Rabia Bibi Anam hassan 21
  • 22. A logic bomb also called SLAG CODE because 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 either Positive event Negative event 1/29/2014 1:35 11/7/2013 Rabia Bibi Anam hassan 22 22
  • 23. SPEAKER: AMMARA FAROOQUI 11736 1/29/2014 11/7/2013 Rabia Bibi 22 23
  • 24. 11/7/2013 Rabia Bibi 24
  • 25. TROJAN HORSES VIRUS • normal computer programs • pretends to be a regular downloadable program • incapable of replicating 1/29/2014 11/7/2013 Rabia Bibi Ammara farooqui 25
  • 26. CONT. most insidious types is that the program claims to rid your computer of viruses but instead introduces viruses onto your computer. 1/29/2014 11/7/2013 Rabia Bibi Ammara farooqui 26
  • 27. 11/7/2013 1/29/2014 Rabia Bibi Ammara farooqui 27 27
  • 28. MACRO VIRUSES • written in a macro language • spread as an e-mail virus • depends on the application rather than the operating system 11/7/2013 1/29/2014 Rabia Bibi Ammara farooqui 28 28
  • 29. CONT.. • "infects" a Microsoft Word or similar application • causes a sequence of actions to be performed automatically 11/7/2013 1/29/2014 Rabia Bibi Ammara farooqui 29 29
  • 30. SPEAKER: MADIHA AHMED ROLL NO: 11761 11/7/2013 MADIHA AHMED 30
  • 31. Virus Entrance Attachment Of Virus Appearance Of Virus Execution Or Running Of Effected Program Computer System Get Effected With Virus 11/7/2013 11/7/2013 Rabia Bibi MADIHA AHMED 31 31
  • 32. There are literally dozens of ways for viruses to enter into the computer system. 11/7/2013 11/7/2013 Rabia Bibi MADIHA AHMED 32 32
  • 33. Virus attaches to its target file or software present in computer system . 11/7/2013 11/7/2013 Rabia Bibi MADIHA AHMED 33 33
  • 34. : It can appear in the form of code, scripts, active content, other software and email attachments. 11/7/2013 11/7/2013 Rabia Bibi MADIHA AHMED 34 34
  • 35. EXECUTION OR RUNNING OF PROGRAM 11/7/2013 11/7/2013 REPLICATIO N Rabia Bibi MADIHA AHMED 35 35
  • 36. 11/7/2013 11/7/2013 Rabia Bibi MADIHA AHMED 36 36
  • 37. Anti virus noor-ul-ainn roll no: 11 77 3 11/7/2013 7/11/2013 Noor-ul-ainn 7/11/2013 Rabia Bibi Noor-ul-ainn 37 37
  • 38. Definition: A • “ ntivirus" 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. 11/7/2013 7/11/2013 Noor-ul-ainn Rabia Bibi P R O T E C T 7/11/20 38 38
  • 39. 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. 11/7/2013 7/11/2013 Noor-ul-ainn Rabia Bibi 39 39
  • 40. 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. 11/7/2013 7/11/2013 Noor-ul-ainn Rabia Bibi 40 40
  • 41. 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. 11/7/2013 7/11/2013 Noor-ul-ainn Rabia Bibi 41 41
  • 42. 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. 7/11/2013 11/7/2013 Noor-ul-ainn Rabia Bibi 42 42
  • 43. Examples: • Examples of common antivirus programs include Norton Antivirus, Kaspersky Anti-Virus, and ZoneAlarm Antivirus. slide 7 11/7/2013 Rabia Bibi antivirus 43 43
  • 44. 44 11/7/2013 Rabia Bibi Hira Arshad 11/07/2013 44
  • 45. 45 11/7/2013 Hira Arshad Rabia Bibi 11/07/2013 45
  • 46. Hira Arshad 46 11/7/2013 Rabia Bibi 11/07/2013 46
  • 47. 47 Hira Arshad 11/7/2013 Rabia Bibi 11/07/2013 47
  • 48. 48 11/7/2013 Hira Arshad Rabia Bibi 11/07/2013 48
  • 49. 49 11/7/2013 Hira Arshad Rabia Bibi 11/07/2013 49
  • 50. http://www.makeuseof.com/tag/history-computerviruses-worst-today-case-wondering/  http://inventors.about.com/od/computerviruses/ http://www.howstuffworks.com/virus2.htm www.buzzle.com/articles/different-types-ofcomputer-viruses.html http://www.computervirusremovalguide.com/a-brieflook-at-the-history-of-computer-viruses.php www.makeuseof.com/tag/types-computer-viruseswatch/ www.webopedia.com/TERM/V/virus.html/ 11/7/2013 Rabia Bibi 50
  • 51. 11/7/2013 Rabia Bibi 51