Internet Safety Tutorial

Lesson #9 - The Truth About Viruses

About 4 times a day I get questions regarding what is going wrong with a computer system.  2 of those questions ask how to get rid of a virus where there is no proof a virus is at fault.  The other 2 generally don't even ask about a virus, and assume it is a hardware/software problem.  Today we're going to look at how viruses affect your system, and how to tell if one is to blame.

Viruses And Your Computer

Generally there are about 4 different affects a virus can have on your system  The most obvious is the e-mail script, where an e-mail virus replicates itself by sending itself through your e-mail address list.  The second symptom is sudden file name change or data change.  The third is the disappearance of files.  The last is the failure of your system to boot.  Most viruses use a combination of these affects in an escalating form.

  1. E-mail Scripts - This becomes obvious when your friends e-mail you back telling you you sent them a virus.
  2. Name Change/Data Change - This shows itself when Windows or other applications give you "Missing File" errors.  Data files will suddenly have changes, and applications will fail to load.
  3. File Deletions - This is normally seen by the same "Missing File" errors, but often will cause Windows to fail to boot properly.
  4. System Crashes - When a system crashes and refuses to boot again, this is normally the sign of a virus.  If you re-install the operating system and the problem re-occurs, you probably have a boot sector virus.

Because these symptoms all work together, you'll normally see one symptom quickly followed by the next in the list.

What Do Viruses Do?

The normal progression of a virus after infecting your system is to replicate itself.  This involves affecting more files on your system as well as attempting to spread on to other systems.  This is the e-mail script section, where the virus will search through your address book and send itself to other computers.  If you get an e-mail from a friend asking why you sent a file that you don't remember sending, you probably have a virus.

The second thing a virus does depends on it's intentions.  Some viruses are comical, such as the cookie monster virus.  (Cookie monster appears on the screen and won't go away until you type "Give Cookie Monster A Cookie".)  Others are more dangerous.  (Chernobyl was designed to wipe a hard drive clean.)  Some are a pain in the butt.  (A boot sector virus will stay even if you re-install your operating system.)

How Do I Stop Viruses From Affecting My Computer?

This is simple.  #1 Install a virus scanner software.  #2 Install a firewall.  #3 Don't open e-mails with attachments with the file extensions .com, .bat, .exe, .zip, or .js.  Virus scanners remove viruses after they are installed, and stop new ones from installing.  Firewalls stop people from remote IPs gaining access to your computer and installing a virus.  

Not opening those e-mail attachments is the #1 way to stop viruses from spreading.  Sure they have funny names and look cool, but they are only there to harm your system and don't care that you didn't know it was a virus.  Even if you know the person sending the file, DON'T open it unless you asked for that file or that person told you previously they were sending it.  95% of viruses on computers today could be eliminated with this simple step.

What Do I Do If I'm Infected?

If you're infected, you better hope you caught a nice virus. 

If you can't get McAfee to clean your system, you can at least get it to tell you what you have to do.  The main reason I support McAfee is because they have the best library of fixes for all the different viruses.  So even if McAfee can't solve your problem, it can at least tell you how to fix it yourself.  You can also purchase virus scanning software on that site.


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