Neither ScanDisk nor the defragmentation command will remove a virus from your system. You need to install a virus protection program, or two or three!

What is a virus?
A computer virus is a program that can make copies of itself. Most computer viruses do nothing more than this and are more of an annoyance than a danger. Some computer viruses, though, may also harm data and programs stored on a computer.

What types of viruses are there?

• Program viruses infect computer programs and become active when the infected program is run.
• Boot sector viruses infect diskettes and hard disks and become active when an infected disk is used to start the computer. (On a Macintosh, merely inserting an infected disk can activate a virus.)
• Macro viruses infect documents (files) through the macro programming capabilities of some newer programs. Macro viruses become active when an infected document is opened, and the program opening the document has its macro capabilities turned on (enabled). As of late 1997, only documents created with Microsoft Word version 6 or later (Windows and Macintosh versions), Excel (5.0 for Windows 3.x and Windows NT, and 7.0 for Win95), and Lotus Ami Pro have seen infections.
• Trojan horse programs are designed to do something (usually something malicious) other than their supposed purpose. Trojan horse programs are sometimes classified with viruses. However, because they don't make copies of themselves, they are not true viruses.

  How do viruses spread?

  • A macro virus becomes active when a document infected with the virus is opened using the program it is designed to attack. The program must have its ability to run macros enabled (turned on). Generally, when a virus in a document becomes active, it will spread to global settings for the application, so that other documents will become infected when they are opened. When an infected document is opened on another computer, the global settings used by that copy of the application will be infected as well.
  • A boot sector virus infects hard disks and diskettes. If a computer is re-booted or its power is turned on while an infected diskette is in drive A, the virus will spread to the hard disk, even if the diskette is not capable of starting up the computer. Once the hard disk is infected, all diskettes used in the computer will be infected and can spread the infection to other computers. On Macintoshes, a boot sector virus can become active when an infected diskette is inserted in a diskette drive because the Macintosh reads the diskette immediately.
  • A program virus becomes active when a program infected with a virus is run.Once a program virus is active, it will usually infect other programs on the computer. If a copy of an infected program is moved to and run on another computer, it can then infect programs on that computer.

  Can a virus spread through e-mail?

  • It is possible to get a virus through e-mail but only in very limited circumstances. If you are using an e-mail program that can handle files attached to an e-mail message, you may be vulnerable. To get an infection, the attachment must carry an infection and the e-mail program must be set to do something automatically when it sees the attachment. If the attatchment is a program, the e-mail program would have to run the program without asking you; if the attachment is a document, the e-mail program would have to run a program to open that document. In the latter case (opening a document), the program would have to be configured to allow running macros. If any of the above circumstances are not true for you, you're in no danger of being infected by a virus when you read e-mail. If you save the attachment from an e-mail message, and it is a program or a file that might contain a macro virus, you should scan it with an anti-virus program before opening it.

  How to Practice Safe Computing
  

  • Download or buy an anti-viral program. A common component of anti-virus software is a "resident" program that checks files and disks for virus infections before letting you use them. (A "resident"program runs when you start your computer, and it continues to run "behind the scenes" while you use the computer.) If it finds something that seems to be infected, it will warn you and probably will not let you continue whatever you were doing until you fix the problem. You may need to run a separate program to remove the virus from the infected file(s) or disk(s). Install it. Open the ReadMe file and read it. RTFM.
  • Most anti-virus software requires that no virus is active when the software runs. To start an IBM-compatible computer without activating a virus, you must boot the computer from a diskette that is not infected with a virus. After the computer is operating, anti-virus software can check for viruses, and in most cases, remove them. Macintosh computers can be checked for viruses after starting the computer normally (without using a diskette). After running the program, also check your diskettes. A list of various anti-viral programs:
    • Disinfectant Antiviral Utility version 3.7 Macintosh antiviral software. This release identifies and removes all known non-Hypercard Macintosh viruses. This is version 3.7 of Disinfectant, John Norstad's venerable freeware anti-virus utility. It has been updated to detect a variant on the MBDF B virus that the Disinfectant INIT in version 3.6 caught, but which the 3.6 application missed.
    • F-PROT F-Prot is most useful on PC's running MS-DOS or Windows 3.x. For PC's running Windows 3.x or Windows 95, it includes the program F-Macrow which will check for macro viruses (these only occur in the files of a few Windows-based programs). On PC's running Windows 95, F-Prot cannot be used to check automatically for boot sector or program viruses, although it can be used to check for these viruses manually. anti-virus program
    • McAfee VirusScanAward-winning Hunter scanning technology accurately pinpoints both known and new macro, polymorphic, boot, file,multi-partite,stealth, mutating and encrypted viruses.
    • ViruSafe from Eliashim works everytime you download from the Internet. Don't surf without it!
    • Norton AntiVirus, NAV 4.0 from Symantec. PC Magazine editors called NAV "the best combination of virus protection, performance, and usability" and wrote, "NAV provides the best end-user experience of the products we tested. The package includes four informative videos, and installation and setup were among the easiest of the tested products. NAV's drive-oriented interface provides a rich set of scanning options, presented in a clear, well-organized manner."

  Top Ten Viruses:

  • CAP
  • CONCEPT
  • WAZZU
  • ANTIEXE
  • FORM
  • LAROUX
  • ANTICMOS
  • JUNKIE
  • NPAD
  • PARITY BOOT

  A Few of the Many Virus Hoaxes:

  • WIN A HOLIDAY hoax
  • Sandman homepage warning
  • Bill Gates Email Tracking chain letter
  • Penpal Greetings hoax
  • Join the Crew
  • Join the Club
  • Bud Frogs warning
  • Francesca chain letter
  • Hackingburgh
  • AOL4FREE.COM hoax and A4F-Spoof trojan
  • Cancer chain letter
  • YUKON3U.mp JPG hoax
  • Hacker Riot
  • Good times *one of the first of the great hoaxes
  • Irina
  • PKZIP300
  • Microsoft home page hoax