Virus Info

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A VIRUS is a program (a block of executable code) which attaches itself to, overwrites or otherwise replaces another program in order to reproduce itself without the knowledge of the PC user.

Most viruses are comparatively harmless, and may be present for years with no noticeable effect: some, however, may cause random damage to data files (sometimes insidiously, over a long period) or attempt to destroy files and disks. Others cause unintended damage. Even benign viruses (apparently non-destructive viruses) cause significant damage by occupying disk space and/or main memory, by using up CPU processing time, and by the time and expense wasted in detecting and removing them.

A TROJAN HORSE is a program intended to perform some covert and usually malicious act which the victim did not expect or want. It differs from a destructive virus in that it doesn't reproduce, (though this distinction is by no means universally accepted). Some types of trojan horses include Remote Access Trojans (RAT), KeyLoggers, Password-Stealers (PSW), and logic bombs - programs that execute destructive instructions when a certain condition is met.

A WORM is a program which spreads (usually) over network connections. Unlike a virus, it does not attach itself to a host program.

The sole, primary goal of all Internet worms is SURVIVAL. Destruction may be a secondary objective, but survival will always be put first by the worm author. Worms work on the principle that "If I send myself to 50 people, chances are high that at least 1 of them can be fooled into running me" - and thus, the worm gains another chance at life. In order to propagate, worms, like real-life worms, require the right environment in order to reproduce. Worms are only possible due to vulnerabilities in certain software packages, and all worms require at least one of these vulnerabilities to exist in order to exploit it and reproduce. As an example, the Word Macro class of viruses & worms requires the "target" to have Microsoft's Word program installed on their computer. If they don't have MS Word installed, the worm is rendered useless on that machine as it cannot exploit Microsoft Word's macro capabilities. The worms principle is now "If I send myself to 50 people, at least 25 of those should have Microsoft Word, and at least 1 of them can be fooled into running me".

Top 10 Tips to Keep Your Computer Virus-Free

10. Use common sense. It's always better to err on the side of safety. If you're unsure about an attachment, delete it. Especially if it's from a source you don't recognise. If there are tempting animations on a site that look highly unprofessional, don't download them.

9. Scan floppies before using them. This is always important, but especially if you are using the disk to carry information between one computer and another. You could easily pick up a virus from an insecure network and introduce it into your system. Running a virus scan before launching any of the programs on the disk will prevent infection.

8. Don't share floppies. Even a well-meaning friend may unknowingly pass along a virus, Trojan horse, or worm. Label your floppies clearly so you know they're yours and don't loan them out. If a friend passes you a foreign floppy, suggest an alternative method of file sharing.

7. Don't boot from a floppy disk. Floppies are one of the most common ways viruses are transmitted. If you are using a floppy while working on your computer, remove it when you shut the machine off or the computer will automatically try to boot from the floppy, perhaps launching any viruses on the disk.

6. Don't download programs from the Web. Unreliable sources such as Internet newsgroups or Web sites that you haven't heard of may be willing providers of viruses for your computer. Avoid downloading files you can't be sure are safe. This includes freeware, screensavers, games, and any other executable program - any files with an ".exe" or ".com" extension, such as "coolgame.exe." Check to see if the site has anti-virus software running on their side. If you do have to download from the Internet, be sure to scan each program before running it. Save all downloads to one folder, then run virus checks on everything in the folder before using it.

5. Update your anti-virus software frequently. An anti-virus program is only as good as the frequency with which it is updated. New viruses, worms, and Trojan horses are born daily, and variations of them can slip by software that is not current. Norton AntiVirus™ has a feature that searches for new virus definitions every time you go online, so you are always up to date.

4. Get immediate protection. Configure your anti-virus software to boot automatically on start-up and run at all times. This will provide you back-up protection in case you forget to scan an attachment, or decide not to. And in case you forget to boot up your anti-virus software, configuring it to start by itself will ensure you get immediate protection anyway.

3. Scan all incoming email attachments. Be sure to run each attachment you plan to open through the anti-virus check. Do this even if you recognise and trust the sender; malicious code, like Trojan horses, can slip into your system by appearing to be from a friendly source.

2. Don't automatically open attachments. Be sure your email program doesn't automatically download attachments. This will ensure that you can examine and scan attachments before they run. Refer to your email program's safety options or preferences menu for instructions.

1. Install reliable anti-virus software. Anti-virus software scans files regularly for unusual changes in file size, programs that match the software's database of known viruses, suspicious email attachments, and other warning signs. It's the most important step you can take towards keeping your computer clean of viruses. Norton Anti Virus, AVG, Panda are just some of the world's leading anti-virus software. This type of Anti Virus software runs continuously in the background of your computer, providing constant protection from viruses, Trojan horses, worms, and other malicious code. To stay up-to-date on the latest online threats, Norton AntiVirus™ automatically updates its virus definitions whenever you're online.

Just in Case. . .
In case a virus finds its way to your computer, due to carelessness, an accident, or anti-virus software that hasn't been updated since you got it for your birthday last year, at least be prepared. Use software such as Norton Ghost to create a backup copy of your computer's hard drive. This way you can revert to the clean, undamaged version of your computer.