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DO YOU HAVE A VIRUS?

DO YOU HAVE A VIRUS? COMPUTER VIRUS: Potentially damaging computer program designed to infect other software or files by attaching itself to the software or files with which it comes in contact.

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DO YOU HAVE A VIRUS?

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  1. DO YOU HAVE A VIRUS?

  2. COMPUTER VIRUS: Potentially damaging computer program designed to infect other software or files by attaching itself to the software or files with which it comes in contact.

  3. A virus is illegal computer code that can do such things as alter programs or destroy data. Also, the virus can copy itself onto programs, thereby spreading its damaging effects. What is a virus?

  4. How do viruses spread? • A piece of software that has a virus attached to it is called a host program. • Usually the virus is spread when the host program is shared. • If the host program is copied, the virus also is copied. • It infects software with which it comes into contact.

  5. Types of Electronic Infections: • Boot Sector Virus • File Virus • Macro Virus • Trojan Horse

  6. Types of Electronic Infections • Time Bomb • Worm • Logic Bomb • Attachment

  7. Boot Sector Virus • Infects computer at the start-up files. • Will not allow the computer to boot up or start.

  8. File Virus • Virus that infects files and programs on hard drive.

  9. Macro Virus • Virus in a macro that will destroy the macro

  10. Trojan Horse • Virus that sneak inside another file that can be executed at a specific time or under specific circumstances

  11. Time Bomb • Something that threatens to have an abruptly disastrous outcome in the future. It is time specific that will hit and attack your computer

  12. Worm • Malicious program that replicates itself until it fills all the storage space on a drive or network

  13. Logic Bomb • A computer virus that remains hidden until it is triggered when certain specific conditions are met.

  14. Attachment • A file that is attached to another file. • This does not necessarily mean an attachment to an e-mail. You should never open e-mails or attachments from people you don’t know. • A virus can attach to a perfectly legitimate file

  15. Why are viruses not detected immediately? People who copy and keep the host software are unaware that the virus exists, because the virus is designed to hide from computer users for weeks or even months.

  16. When does a virus attack? A virus usually attacks at the specific times or dates determined by the person who wrote the virus code. When the predetermined time or date registers on the internal clock of the computer, the virus attacks. Sometimes the virus code will leave a message letting you know that the virus has done its damage.

  17. People Create Viruses: • Same psychology that drives vandals and arsonists. • Thrill of watching things blow up. • Bragging rights or the thrill of doing it.

  18. Preventing Virus Problems • Back up essential files • Delete e-mail file attachments • Prepare an emergency system boot disk • Block Word macro viruses

  19. Downloading • Read carefully any pop-ups that want you to download material. • If what the pop-up asks you to download is from Macromedia you can feel confident about it’s security. Flash or Shockwave • Any other site you are taking your chances.

  20. Downloading • The sites you frequent Music and Games are targets for viruses. • These sites will be the place where viruses will enter your computer.

  21. Sleazeware • Sleazeware is another term for spyware, adware, malware, trackware, foistware, trojans, and other computer programs that sleaze into your computer, either as a hidden component or by tricking you into downloading them. Reynolds, Ben. Technology and Learning pg. 33 January 2005

  22. Sleazeware • Once in your machine the program phones home for purposes ranging from simply reporting where you browse to downloading keyloggers Reynolds, Ben. Technology and Learning pg. 33 January 2005

  23. Keyloggers • Keyloggers record keystrokes, including passwords and credit card numbers, and then send them to another computer. Reynolds, Ben. Technology and Learning pg. 33 January 2005

  24. Sleazeware • Here are some ways to stop sleazeware before it filthies your computer. Reynolds, Ben. Technology and Learning pg. 33 January 2005

  25. Preventing Sleazeware • Only use Pop-up blockers from reputable companies or Internet Service Providers. • Test your pop-up blocker thoroughly: www.kephyr.com/popupkillertest is a good test. Reynolds, Ben. Technology and Learning pg. 33 January 2005

  26. Preventing Sleazeware • Don’t Download a pop-up blocking program from an unknown source or you may be downloading sleazeware. Reynolds, Ben. Technology and Learning pg. 33 January 2005

  27. Read the End User Licensing Agreement • Read any notes about the product on the download site, and any readme files downloaded with the program before installing it. Reynolds, Ben. Technology and Learning pg. 33 January 2005

  28. Preventing Sleazeware • Avoid free software with cute names. • “Cool”, “fun”, “better”, “look”, and “keen”, are danger signs for sleazeware. Reynolds, Ben. Technology and Learning pg. 33 January 2005

  29. Preventing Sleazeware • If your tempted to download do a web search on the product name followed by a space and “spyware” • Example “coolfunkeenwebdoodles spyware” Reynolds, Ben. Technology and Learning pg. 33 January 2005

  30. Preventing Sleazeware • Install SpywareBlaster if you know your computer is sleaze free. Reynolds, Ben. Technology and Learning pg. 33 January 2005

  31. Preventing Sleazeware • Use the Windows Update button Reynolds, Ben. Technology and Learning pg. 33 January 2005

  32. Downloading • Downloading from the Internet is your greatest chance of getting a virus.

  33. Helpful Hints to Avoid Viruses • Obtain software only from trusted sources. • Use a safe Web browser and e-mail client. • Install anti-virus software, and keep it update. • Scan all newly-obtained disks, programs, and files. • Install a firewall program, especially if on cable or DSL.

  34. Computer Virus • Set of program instructions that attaches itself to a file, reproduces itself, and/or spreads to other files • It can • Corrupt files • Destroy data • Display irritating messages • Corrupt computer systems

  35. Spreading Viruses • Viruses spread because people distribute infected files by exchanging disks and CDs, sending e-mail attachments, and downloading documents from the Internet. • Viruses attach themselves to files with .exe, .com, or .vbs filename extensions • When you open the infected file, the virus opens and waits to infect the next program you run or disk you use

  36. Spreading Viruses (continued) • Viruses have the ability to lurk in a computer for days or months, quietly replicating themselves • You may not even know your computer has a virus, thus making it easier to spread the virus

  37. Trigger Events • An event that activates a task often associated with a computer virus • Time Bomb • Watches for the PC clock to reach a certain date to activate the virus • Example • Michelangelo virus • Damages files on March 6 the artist’s birthday • Logic Bomb • Watches for a specific set of input to activate the virus

  38. Classification of Viruses

  39. File Virus • Virus that attaches to an application program • Example • Chernobyl • Notorious for overwriting a section of the hard disk, making it impossible to access data

  40. Boot Sector Virus • Infects the system files that your computer uses every time it is turned on • Cause widespread damage and recurring problems • Example • Stoned Virus • Every time you turn on your computer the virus is activated and infects any non-write-protected files including your hard disk

  41. Macro Virus • Macro • A miniature program that usually contains legitimate instructions to automate a document or task • This virus infects a macro • Example • Melissa Virus • Attaches itself to Microsoft Word documents • Codemas Virus • Attaches itself to Microsoft Excel spreadsheets

  42. Other Viruses

  43. Trojan Horse • Computer program that seems to perform one function while actually doing something else • Different from a virus because it does not make copies of itself • Different tasks that can be affected • Stealing passwords • Deleting files

  44. Trojan Horse Example

  45. Worm • Software program designed to enter a computer system usually through a network, through security holes and then replicate itself • Spreads from computer to computer

  46. Worm Example

  47. Protecting yourself from viruses • Antivirus software • Set of utility programs that looks for and eradicates a wide spectrum of problems, including viruses, Trojan horses, and worms • Example • McAfee Virus Scan • Don’t open e-mails attachments that have strange names or are from people you don’t recognize

  48. Resource Parsons, June Jamrich, and Dan Oja. Computer Concepts. Boston: Course Technology - Thompson Learning, 2002.

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