Computer viruses


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Types of Virues

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Computer viruses

  1. 1. COMPUTER VIRUSES Presented by: Aditi Ambekar Angela Mary Binoy Annies Minu SathiyaSeelan
  2. 2. SICK OF COMPUTER VIRUSES? What they are… Where they come from… Why they are here…
  3. 3. Index 1. History 2.Concept 3. Symptoms 4. Types Of Infections 6. Types Of Viruses 7.Preventive Measures
  4. 4. History •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 Elk Cloner, and was the first computer virus to appear outside the computer where it was created in.
  5. 5. Everyone who owes a computer might heard a lot about computer viruses…. Virus + DEATH
  6. 6. What is a Computer Virus? A Computer Virus is a program that can copy itself and infect a computer without the permission or knowledge of the user. A Computer Virus has 2 major characteristics: the ability to replicate itself, and the ability to attach itself to another computer file...
  7. 7. SYMPTOMS The following are a few Symptoms that your 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.
  8. 8. Types Of Infections Malware Viruses Worms Trojan Horses
  9. 9. Types Of Computer Viruses 1. 2. 3. 4. 5. 6. 7. 8. 9. Boot Sector Virus. Browser Hijacker. Direct Action Virus. File Infector Virus. Macro Virus. Multipartite Virus. Polymorphic Virus. Resident Virus. Web Scripting Virus.
  10. 10. Boot Sector Virus • Boot sector virus infects the boot sector of a HDD or FDD. These are also memory resident in nature. As soon as the computer starts it gets infected from the boot sector. Cleaning this type of virus is very difficult
  11. 11. Browser Hijacker •Alters the search and error page of a browser and redirects the user to its own page.
  12. 12. Direct Action Virus •They load with the host program into computer’s memory. •They can be crafted with relative ease.
  13. 13. File Infector Virus • This type of virus normally infects program files such as .exe, .com, .bat. Once this virus stays in memory it tries to infect all programs that load on to memory.
  14. 14. Macro Virus • These type of virus infects word, excel, PowerPoint, access and other data files. Once infected repairing of these files is very much difficult.
  15. 15. Multipartite Virus • A hybrid of Boot and Program/file viruses. They infect program files and when the infected program is executed, these viruses infect the boot record. When you boot the computer next time the virus from the boot record loads in memory and then start infecting other program files on disk
  16. 16. Polymorphic Virus • A virus that can encrypt its code in different ways so that it appears differently in each infection. These viruses are more difficult to detect.
  17. 17. Resident Virus • • • • Hides within the computers memory. It activates whenever the OS loads or operates. This virus may be pernicious. It is of 2 types: Fast Infector. Slow Infector. • Removal of this virus is bit tricky. • It may be designed to block the actions of Anti Virus programs.
  18. 18. Web Scripting Virus There are few website that execute complex code with the purpose to provide interesting content ,these codes often get exploited and due to this a virus becomes able to infect a machine and to take actions on a machine via website. This particular virus is called web scripting virus
  19. 19. Preventive Measures •Be Sure to download only from Reputable Websites. •Install a Quality Firewall Program. •Do not open Suspicious Emails or Attachment. •Most Importantly make sure that you have a good Anti Virus program installed.
  20. 20. CONCLUSION
  21. 21. THANK YOU!