Virus presentation


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Virus presentation

  1. 1. 02/28/12
  2. 2. <ul><li>A kind of software programs </li></ul><ul><ul><li>produced by unknown people and harmful to the computers </li></ul></ul><ul><li>Some varieties of these software are the </li></ul><ul><ul><li>Viruses , Worms and Trojan horses </li></ul></ul>02/28/12
  3. 3. <ul><li>The term “Virus&quot; is often used in common </li></ul><ul><ul><li>to describe all kinds of malware (malicious software) including   adware  and spyware  programs that do not have the reproductive ability. </li></ul></ul>02/28/12
  4. 4. <ul><li>Trojan horse perform a desirable function for the user in addition to the expected function </li></ul><ul><li>Leaks information </li></ul><ul><li>Usually does not reproduce </li></ul>02/28/12
  5. 5. <ul><li>A worm is a self replicating malware computer program, which uses a computer network to send copies of itself to other computers and it may do so without any user intervention. It does not need to attach itself to an existing program. </li></ul>02/28/12
  6. 6. <ul><li>Sometimes display unwanted messages </li></ul><ul><li>Some tend to destroy programs or data </li></ul><ul><li>Clog computer memory and hence sometimes result </li></ul><ul><li>in system crashes </li></ul><ul><li>Format hard disks, Damage programs, Delete files </li></ul>02/28/12 Viruses
  7. 7. <ul><li>Simply replicate themselves </li></ul><ul><li>Presents text, video, or audio messages making the user know their presence </li></ul><ul><li>Bug-ridden, and these bugs may lead to system crashes and data loss </li></ul>02/28/12
  8. 8. <ul><li>A viruses can copy itself and infect a computer </li></ul><ul><ul><li>without permission or knowledge of the user </li></ul></ul><ul><li>attaches itself to other software programs or data files </li></ul>02/28/12
  9. 9. <ul><li>Spreads from computer to computer when the host is taken to the uninfected computer </li></ul><ul><ul><li>over a network such as over the Internet or carrying it on a removable medium - a floppy disk, CD, or USB drive </li></ul></ul>02/28/12
  10. 10. <ul><li>Many viruses are existed in the Internet today and new ones are discovered every day. </li></ul><ul><ul><li>spread via downloaded software and data files, and email attachments etc. </li></ul></ul>02/28/12
  11. 11. <ul><li>Some old viruses are installed themselves into the disk boot sector </li></ul><ul><ul><li>runs when the user boot the computer from the disk </li></ul></ul>02/28/12
  12. 12. <ul><li>Some viruses spread through instant messaging </li></ul><ul><ul><li>A virus, in an infected machine, may send a web address link as a message to other contacting machines </li></ul></ul><ul><ul><li>Thinking the link is from a friend (a trusted source), the recipient may sometimes follow the link to the website. </li></ul></ul>02/28/12
  13. 13. <ul><li>ANSI COBOL </li></ul><ul><li>C/C++ </li></ul><ul><li>Pascal </li></ul><ul><li>VBA </li></ul><ul><li>Unix Shell Scripts </li></ul><ul><li>Javascript </li></ul>02/28/12
  14. 14. <ul><li>Unlike biological viruses, computer viruses do not simply evolve by themselves </li></ul><ul><ul><li>deliberately created by programmers, or by people who use virus creation software </li></ul></ul>02/28/12
  15. 15. <ul><li>Viruses are written as </li></ul><ul><ul><li>research projects, pranks, vandalism, </li></ul></ul><ul><ul><li>to attack the products of specific companies, </li></ul></ul><ul><ul><li>to distribute political messages, </li></ul></ul><ul><ul><li>and financial gain from identity theft, </li></ul></ul><ul><ul><li>spyware, and cryptoviral extortion. </li></ul></ul>02/28/12
  16. 16. <ul><li>Some virus writers </li></ul><ul><ul><li>consider their creations to be works of art </li></ul></ul><ul><ul><li>See virus writing as a creative hobby </li></ul></ul>02/28/12 Releasing computer viruses is a crime in most jurisdictions
  17. 17. <ul><ul><li>File infector virus </li></ul></ul><ul><ul><li>Infect program files </li></ul></ul><ul><ul><li>Boot sector virus </li></ul></ul><ul><ul><li>Infect the system area of a disk </li></ul></ul><ul><ul><li>Master boot record virus </li></ul></ul><ul><ul><li>infect disks in the same manner as boot sector viruses. The difference between these two virus types is where the viral code is located. </li></ul></ul>02/28/12
  18. 18. <ul><ul><li>Multi-partite virus </li></ul></ul><ul><ul><li>Infect both boot records and program files. </li></ul></ul><ul><ul><li>Macro virus </li></ul></ul><ul><ul><li>Infect data files. Example: Microsoft Office Word, Excel, </li></ul></ul><ul><ul><li>PowerPoint and Access files </li></ul></ul>02/28/12
  19. 19. <ul><li>Melissa virus spread in Microsoft Word documents sent via e-mail. </li></ul><ul><li>How it works ? </li></ul><ul><li>Created the virus as word document </li></ul><ul><li>Uploaded to an internet newsgroup </li></ul><ul><li>Anyone who download the document and opened it would trigger the virus. </li></ul><ul><li>Send friendly email messages to first 50 people in person’s address book </li></ul>02/28/12
  20. 20. <ul><li>Melissa Virus was the fastest spreading virus ever seen. </li></ul><ul><li>Forced a number of large companies to shut down their e-mail systems. </li></ul>02/28/12
  21. 21. <ul><li>Contained a piece of code as an attachment. </li></ul><ul><li>Double Click on the attachment triggered the code. </li></ul><ul><li>Sent copies of itself to everyone in the victim’s address book </li></ul><ul><li>Started corrupting files on the victim’s machine. </li></ul>02/28/12
  22. 22. <ul><li>Code Red made huge headlines in 2001 </li></ul><ul><li>It slowed down internet traffic when it began to replicate itself. </li></ul><ul><li>Each copy of the virus scanned the internet for Windows NT or Windows 2000 that don’t have security patch installed. </li></ul><ul><li>Each time it found an unsecured server, the virus copied itself to that server. </li></ul>02/28/12
  23. 23. <ul><li>Designed to do three things </li></ul><ul><li>Replicate itself for the first 20 days of each month </li></ul><ul><li>Replace web pages on infected servers with a page that declares “Hacked by Chinese” </li></ul><ul><li>Launch a concreted attack on the White House Web server. </li></ul>02/28/12
  24. 24. <ul><li>The Morto virus emerged in the summer of 2011. </li></ul><ul><li>It attempts to propagate itself to additional computers via the Remote Desktop Protocol </li></ul><ul><li>(RDP). </li></ul><ul><li>Morto spreads by forcing infected systems to scan for servers allowing RDP login. </li></ul><ul><li>  Once Morto finds an RDP-accessible system, it attempts to log in to a domain or local system account named 'Administrator' using a number of common passwords. </li></ul>02/28/12
  25. 25. <ul><li>To avoid detection by users, viruses </li></ul><ul><li>employ different deception methods </li></ul><ul><ul><li>They do not make themselves to </li></ul></ul><ul><ul><ul><li>change the date of last modified </li></ul></ul></ul><ul><ul><ul><li>increase file sizes </li></ul></ul></ul><ul><ul><ul><li>damage the files </li></ul></ul></ul>02/28/12
  26. 26. <ul><ul><li>They kill the tasks associated with antivirus </li></ul></ul><ul><ul><li>software before it can detect them. </li></ul></ul>02/28/12
  27. 27. <ul><li>Take regular backups (including OS) on different media, unconnected to the system (most of the time) </li></ul>02/28/12 How to prevent damages caused by viruses?
  28. 28. <ul><li>Use backups on optical media like CD and DVD (read-only), as they can no longer be affected by viruses. </li></ul><ul><li>Use an OS on a bootable, to start the computer if the installed OS become unusable. </li></ul>02/28/12 How to prevent damages caused by viruses?
  29. 29. <ul><li>Install reliable anti-virus software </li></ul><ul><ul><li>the most important step you can take towards keeping your computer clean of viruses </li></ul></ul><ul><li>Update your anti-virus software regularly </li></ul><ul><ul><li>variations of viruses and new ones can be slipped if your software is not current </li></ul></ul>02/28/12
  30. 30. <ul><li>Get immediate protection </li></ul><ul><ul><li>Configure your anti-virus software to boot automatically on start-up and run at all times </li></ul></ul>02/28/12
  31. 31. <ul><li>Don't automatically open attachments </li></ul><ul><ul><li>ensure that you examine and scan email and other attachments before they run as they might contain viruses </li></ul></ul><ul><li>Scan all incoming email attachments </li></ul><ul><ul><li>Do not open any email attached files if the subject line is questionable, unexpected or the source (address) is unknown, suspicious or untrustworthy </li></ul></ul>02/28/12
  32. 32. <ul><li>Delete chain emails and junk email </li></ul><ul><ul><li>Do not forward or reply to any of them, they clogs up the network </li></ul></ul><ul><ul><li>Some viruses can replicate themselves and spread through email as a chain </li></ul></ul>02/28/12
  33. 33. <ul><li>Be careful when downloading files from the Internet </li></ul><ul><ul><li>Ensure that the source is a legitimate and reputable one </li></ul></ul><ul><ul><li>save all downloads to one folder and test them with your own anti-virus software before use </li></ul></ul>02/28/12
  34. 34. <ul><li>Backup your files on a regular basis </li></ul><ul><li>Always scan new files for viruses before you use them </li></ul>02/28/12
  35. 35. <ul><li>If your computer is on a network, make sure you have security steps in place to prevent unauthorized users putting files on your computer </li></ul>02/28/12
  36. 36. <ul><li>Take care using USB flash cards, CDs, zip </li></ul><ul><li>and floppy disks </li></ul><ul><ul><li>The more computers flash cards, CDs, zip cards </li></ul></ul><ul><ul><li>and floppies have been used on, the better the chance </li></ul></ul><ul><ul><li>of a virus infecting them – clean them before use </li></ul></ul>02/28/12
  37. 37. 02/28/12