|Protect Your System from Computer Viruses!|
by Therese Nakadomari
In recent years, the explosion in the use of networks and the Internet has created a new avenue for computer viruses to spread at a rapid rate. Earlier viruses used executable files (i.e. files with the extension of .exe, .com, or .bat) and would typically be no more than an annoyance by displaying harmless phrases. The latest viruses are much more sophisticated and able to cause extensive and irreparable damage to files. Some viruses are able to propagate themselves to other computers on the Internet or network causing widespread damage to many systems.
A computer virus (virus) is a program that invades computer systems (both IBM PC and Macintosh) and performs a variety of damaging tasks after a "trigger" event occurs. The "trigger" event can be as simple as starting up a word processing program or opening an e-mail attachment from an e-mail client program. Serious viruses damage the boot sector of the hard drive or alter key system files so that the computer will be unable to boot-up on the next restart.
A Trojan horse is a type of virus which enters a computer system by the sharing of infected program files or when an infected program is downloaded from the Internet. As the name implies, its trademark is deceptiveness. Victims are falsely lured into thinking that their computer systems will benefit from the infected program when in reality, the Trojan horse is waiting for a "trigger" event to occur so that it can activate its damaging behavior.
A computer worm is another type of virus. It infects entire networks of computers by making a copy of itself as it moves from system to system. In recent releases, worms have been found in e-mail attachments and are activated when the victim tries to open the infected file.
With dangerous viruses on the network, what can computer users do to protect their systems? Practice caution when working with files from unknown or questionable sources. Do not open e-mail attachments if you do not recognize the sender. Download files only from reputable Internet sites and be wary when exchanging diskettes or other media between friends. Even with these precautions, viruses will find ways to enter your computer system. Be sure to install an anti-virus software program to guard against virus attacks.
University of Hawaiÿi faculty, staff and students are eligible for a copy of the ITS-supported anti-virus software program free of charge. Send an e-mail message to firstname.lastname@example.org with the following information:
This information is needed to verify your affiliation with the University of Hawaii System in accordance with our site license agreement with Network Associates. Upon verification of your information, you will receive an e-mail message with login procedures and the Web address where upgrades can be downloaded. You will also be added to the uhxvirus-l mailing list. This list is our vehicle for notifying users about new virus alerts and upgrades to the software.
The site-licensed software is also on the ITS CDROM which is available at the Help Desk as supplies last. You will still need to send mail to email@example.com to register and to be added to the uhxvirus-l mailing list.
Anti-virus software programs detect viruses and remove them from computer systems when possible. The software comes with a scanner program that examines selected file types for signs that a virus is present (virus signature). When a virus is detected, the scanner alerts the computer user of the infection and displays the option to remove the virus. Most anti-virus software programs can actively monitor the computer system while it is on to give the computer user a more proactive protection against virus attacks.
Even with active monitoring of computer systems, anti-virus software can only protect against known viruses since the programs need to know the virus signature before it is able to detect the virus. For this reason, update file(s) for anti-virus software are needed every time there is a new virus release.
If a virus is detected on your system, have the anti-virus software remove the virus immediately. It would be prudent to also have the anti-virus scanner program check every file on the computer for additional viruses. If the anti-virus scanner detects a boot sector virus or a virus that causes damage to system files, most of the infected files are being used by the operating system and cannot be cleaned while they are in use. The computer must be shut down and restarted using a bootable floppy disk that was created before the system was infected or from another computer. This bootable floppy disk should have the anti-virus software scanner on it and other necessary files for the scanner to work. The scanner can be run from the diskette to check all files.
Report new viruses immediately to your anti-virus software vendor. Most anti-virus vendors have Web sites with instructions on how to submit infected files of unknown viruses. The vendor can then release an upgrade that includes the new virus signature in the scanner's database.
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