Represented By    Polite Group   Focus on Target <ul><li>Members of group </li></ul><ul><li>Junaid Arshad </li></ul><ul><l...
Topic of Discussion <ul><li>VIRUS </li></ul>
Contents  <ul><li>What is a computer virus?  </li></ul><ul><li>Types of virus </li></ul><ul><li>How to spread a virus? </l...
What is a computer virus? <ul><li>Computer viruses are small software programs that are designed to spread from one comput...
Types of virus <ul><li>There are two main types of virus. </li></ul><ul><li>(1) Residential  </li></ul><ul><li>(2)  Non-re...
Residential <ul><li>A VIRUS doing same thing with the help of Operating system and memory called Residential virus. </li><...
Non-residential . <ul><li>Those viruses searching new file to affect called Non-residential virus. </li></ul><ul><li>A typ...
How to spread a virus <ul><li>A virus might corrupt or delete data on your computer, use your e-mail program to spread its...
Properties of Virus <ul><li>Your computer can be infected by a virus even if files are just copied. Because some viruses a...
Symptoms of Computer virus <ul><li>Deleted files. </li></ul><ul><li>Various messages in files or on programs. </li></ul><u...
Symptoms of Computer virus <ul><li>Causes cross-linked files. </li></ul><ul><li>Causes a &quot;sector not found&quot; erro...
Symptoms of Computer virus <ul><li>After you open and run an infected program or attachment on your computer, you might no...
Symptoms of Computer virus <ul><li>Your computer restarts on its own and then fails to run normally </li></ul><ul><li>Appl...
Action of viruses <ul><li>How viruses may affect files </li></ul><ul><li>Viruses can affect any files; however, usually at...
Action of viruses <ul><li>It can delete files as the file is run - Because most files are loaded into memory, once the pro...
Action of viruses <ul><li>It can convert .exe files to .com files - Viruses may use a separate file to run the program and...
Some other software acts as a virus <ul><li>Worm </li></ul><ul><li>Trojan Horse </li></ul><ul><li>Spyware </li></ul>
worm <ul><li>worm </li></ul><ul><li>A program or algorithm that replicates itself over a computer network and usually perf...
Trojan Horse <ul><li>Trojan Horse </li></ul><ul><li>A destructive program that masquerades as a benign application. Unlike...
Spyware <ul><li>Spyware programs are different from viruses, some can behave like viruses and pose similar and other risks...
Steps to help avoid viruses   <ul><li>Use an Internet firewall  </li></ul><ul><li>Subscribe to antivirus software and keep...
 
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Viruses

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This presentation is prepare by Polite group from GCU Faisalabad.The members of polite group are Syed Mubashair Abid.Ch.Junaid Arshad.Ch.Uzair Zia.Hafiz Jawad Ahmed.

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Viruses

  1. 1. Represented By Polite Group Focus on Target <ul><li>Members of group </li></ul><ul><li>Junaid Arshad </li></ul><ul><li>Mubashair Abid </li></ul><ul><li>Hafiz Jawad Nadeem </li></ul><ul><li>Uzair Zia </li></ul>
  2. 2. Topic of Discussion <ul><li>VIRUS </li></ul>
  3. 3. Contents <ul><li>What is a computer virus? </li></ul><ul><li>Types of virus </li></ul><ul><li>How to spread a virus? </li></ul><ul><li>Properties of virus </li></ul><ul><li>Symptoms of Computer virus </li></ul><ul><li>Action of virus </li></ul><ul><li>Some other software acts as a virus </li></ul><ul><li>Steps to help avoid viruses </li></ul>
  4. 4. What is a computer virus? <ul><li>Computer viruses are small software programs that are designed to spread from one computer to another and to interfere with computer operation. </li></ul><ul><li>Like a human virus, a computer virus can range in severity. It can damage your hardware, software or files. </li></ul><ul><li>Viruses can also replicate themselves. </li></ul><ul><li>A virus is dependent upon the host file or boot sector, and the transfer of files between computers to spread </li></ul>
  5. 5. Types of virus <ul><li>There are two main types of virus. </li></ul><ul><li>(1) Residential </li></ul><ul><li>(2) Non-residential . </li></ul>
  6. 6. Residential <ul><li>A VIRUS doing same thing with the help of Operating system and memory called Residential virus. </li></ul><ul><li>A type of computer virus that does not store or execute itself from the computer memory. </li></ul>
  7. 7. Non-residential . <ul><li>Those viruses searching new file to affect called Non-residential virus. </li></ul><ul><li>A type of computer virus that store or execute itself from the computer memory. </li></ul>
  8. 8. How to spread a virus <ul><li>A virus might corrupt or delete data on your computer, use your e-mail program to spread itself to other computers, or even erase everything on your hard disk. </li></ul><ul><li>Computer viruses are often spread by attachments in e-mail messages or instant messaging messages. That is why it is essential that you never open e-mail attachments unless you know who it's from and you are expecting it. </li></ul><ul><li>Viruses can deceit us as attachments of funny images, greeting cards, or audio and video files. </li></ul><ul><li>Computer viruses also spread through downloads on the Internet . They can be hidden in illicit software or other files or programs you might download. </li></ul>
  9. 9. Properties of Virus <ul><li>Your computer can be infected by a virus even if files are just copied. Because some viruses are memory resident, as soon as a diskette or program is loaded into memory, the virus then attaches itself into memory and then is capable of infecting any file on the computer you have access to. </li></ul>
  10. 10. Symptoms of Computer virus <ul><li>Deleted files. </li></ul><ul><li>Various messages in files or on programs. </li></ul><ul><li>Changes volume label. </li></ul><ul><li>Marks clusters as bad in the FAT. </li></ul><ul><li>Randomly overwrites sectors on the hard disk. </li></ul><ul><li>Replaces the MBR with own code. </li></ul><ul><li>Create more than one partition. </li></ul><ul><li>Attempts to access the hard disk drive, which can result in error messages such as: </li></ul><ul><li>Invalid drive specification . </li></ul>
  11. 11. Symptoms of Computer virus <ul><li>Causes cross-linked files. </li></ul><ul><li>Causes a &quot;sector not found&quot; error. </li></ul><ul><li>Cause the system to run slow. </li></ul><ul><li>Logical partitions created, partitions decrease in size. </li></ul><ul><li>A directory may be displayed as garbage. </li></ul>
  12. 12. Symptoms of Computer virus <ul><li>After you open and run an infected program or attachment on your computer, you might not realize that you've introduced a virus until you notice something isn't quite right. </li></ul><ul><li>Here are a few primary indicators that your computer might be infected: </li></ul><ul><li>Your computer runs more slowly than normal </li></ul><ul><li>Your computer stops responding or locks up often </li></ul><ul><li>Your computer crashes and restarts every few minutes </li></ul>
  13. 13. Symptoms of Computer virus <ul><li>Your computer restarts on its own and then fails to run normally </li></ul><ul><li>Applications on your computer don't work correctly </li></ul><ul><li>Disks or disk drives are inaccessible </li></ul><ul><li>You can't print correctly </li></ul><ul><li>You see unusual error messages </li></ul><ul><li>You see distorted menus and dialog boxes </li></ul>
  14. 14. Action of viruses <ul><li>How viruses may affect files </li></ul><ul><li>Viruses can affect any files; however, usually attack .com, .exe, .sys, .bin, .pif or any data files - Viruses have the capability of infecting any file; however, will generally infect executable files or data files, such as word or excel documents that are opened frequently and allow the virus to try infecting other files more often. </li></ul><ul><li>Increase the files size - When infecting files, virtues will generally increase the size of the file; however, with more sophisticated viruses these changes can be hidden. </li></ul>
  15. 15. Action of viruses <ul><li>It can delete files as the file is run - Because most files are loaded into memory, once the program is in memory the virus can delete the file used to execute the virus. </li></ul><ul><li>It can corrupt files randomly - Some destructive viruses are not designed to destroy random data but instead randomly delete or corrupt files. </li></ul><ul><li>It can cause write protect errors when executing .exe files from a write protected disk - Viruses may need to write themselves to files that are executed; because of this, if a diskette is write protected, you may receive a write protection error. </li></ul>
  16. 16. Action of viruses <ul><li>It can convert .exe files to .com files - Viruses may use a separate file to run the program and rename the original file to another extension so the exe is run before the com. </li></ul><ul><li>It can reboot the computer when executed - Numerous computer viruses have been designed to cause a computer to reboot, freeze, or perform other tasks not normally exhibited by the computer. </li></ul>
  17. 17. Some other software acts as a virus <ul><li>Worm </li></ul><ul><li>Trojan Horse </li></ul><ul><li>Spyware </li></ul>
  18. 18. worm <ul><li>worm </li></ul><ul><li>A program or algorithm that replicates itself over a computer network and usually performs malicious actions </li></ul>
  19. 19. Trojan Horse <ul><li>Trojan Horse </li></ul><ul><li>A destructive program that masquerades as a benign application. Unlike viruses, Trojan horses do not replicate themselves </li></ul>
  20. 20. Spyware <ul><li>Spyware programs are different from viruses, some can behave like viruses and pose similar and other risks. </li></ul>
  21. 21. Steps to help avoid viruses <ul><li>Use an Internet firewall </li></ul><ul><li>Subscribe to antivirus software and keep it current. </li></ul><ul><li>Never open an e-mail attachment from someone you don't know. </li></ul><ul><li>Avoid opening an e-mail attachment from someone you know, unless you know exactly what the attachment is. The sender may be unaware that it contains a virus. </li></ul>

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