What is a Virus?

A virus is a piece of software that has been written to enter you computer system and infect your files without you knowing. Most copy themselves and try to infect as many files and systems as they can.

Types of Viruses

Boot sector viruses are spread when an infected floppy disk is left in the drive and the system is rebooted, at which stage the virus is read from the infected boot sector and is then written to the hard-drive's master boot disk - the first place your system reads when you start up. The virus will therefore be loaded onto the system's memory every time you boot up.
Program or file viruses attach themselves to executable (.exe) programs, and once the infected program is run, the virus is transferred to your system's memory and may copy itself further.
Macro viruses, the most common type, infect files run by applications that use macro's, such as MS Word or Excel. The virus looks like a macro in the file, and executes commands when the file is opened.
Mutilpart viruses have characteristics of both sector boot and file viruses, and may start in the boot sector or applications, and spread.
A worm is a program that copies itself but does not necessarily infect other programs, although they can cause widespread havoc. They copy from system to system without using host files, and therefore are not true viruses.
Trojan Horses hide themselves in seemingly harmless programs, until a certain condition causes it to open. They do not however replicate themselves, so also cannot be considered to be true viruses.

How do you know if you have a virus?

Common symptoms include: strange messages or displays on your monitor, strange sounds/music, your system has less memory than it should, a disk name has changed, programs or files are missing, unknown programs or files have been created, or some of your files suddenly don't work properly.

Protecting against viruses

Your best defense against viruses is to install anti-virus software and update it and scan regularly. Most anti-virus software can be set to scan all removable media and downloaded files. Check with your supplier to find out how to keep your software up to date. Other ways to protect your system include taking floppy disks out when shutting down or restarting, not opening emails from unknown addresses, verifying suspicious attachments with the sender (even if you know them) and backing up your data on a regular basis.

What to do if you have a Virus?

If you have anti-virus software installed and if it has found a virus, first get it to clean/disinfect the files. If this doesn't work, you may have to delete these files from your system. In extreme cases, you might need to reformat your hard-drive, destroying everything on it. You will then need to reinstall your software and data - which is why back-ups is so important! If this happens, it is a good idea to install the anti-virus software first, just to be safe. Finally, it might be a good idea to contact all the people that you have recently exchanged data with to let them know that your system has been infected so that they can check theirs.

Remember to always keep your software updated and not to open suspicious emails, and you should be safe!

The following anti-virus software is available from Computer Mania in Cape Town - (021) 423-0717:
McAfee Virus Scan v.6 - R475.00
Panda Titanium - R375.00
Norton 2002 - R650.00

Want to receive regular virus alerts? Email webmaster@bizland.co.za with the subject "virus subscription".

Back to www.bizland.co.za