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Internet Tips InformationAll Simply simply about Computer Viruses
by:
Kara Glover
Feel Free to reprint this article in newsletters and on websites, with resource box included. If you use this article, please send a brief message to let me cognize wherever
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URL: http://www.karathecomputertutor.com
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Date of copyright: Gregorian calendar month 2004
All Simply simply about Computer Viruses
by Kara Glover
kara333@earthlink.net
Your computer is as slow as molasses. Your mouse freezes every 15 minutes, and that Microsoft Word program simply won’t seem to open.
You mightiness have a virus.
Just what exactly is a virus? What kind is in your computer? How did it get there? How is it spreading and wreaking such havoc? And why is it bothering with your computer anyway?
Viruses are pieces of programming code that do copies of themselves, or replicate, inside your computer without asking your explicit written permission to do so. Forget acquiring your permission down on paper. Viruses don’t bother to seek your permission at all! Really invasive.
In comparison, there are pieces of code that mightiness replicate inside your computer, say thing
your IT guy thinks you need. But the code spreads, possibly throughout your office network, with your consent (or at least your IT guy’s consent). These types of replicating code are called agents, aforesaid Jimmy Kuo, a research fellow with McAfee AVERT, a research arm of anti-virus software-maker McAfee Inc.
In this article, though, we’re not talking simply about the nice guys, or the agents. We’ll be talking simply about the bad guys, the viruses.
A long, long time ago in computer years, like five, most viruses were comprised of a similar breed. They entered your computer possibly through an email attachment or a floppy disk (remember those?). Then they attached themselves to one of your files, say your Microsoft Word program.
When you opened your Microsoft Word program, the virus replicated and attached itself to another files. These could be another random files on your hard drive, the files furthest away from your Microsoft Word program, or another files, depending on how the virus writer wanted the virus to behave.
This virus code could contain hundreds or thousands of instructions. Once
it replicates it inserts those instructions, into the files it infects, aforesaid Carey Nachenberg, Chief Designer at Symantec Research Labs, an arm of anti-virus software-maker Symantec. Corp.
Because so galore another types of viruses exist now, the kind simply delineated is called a classic virus. Classic viruses still exist but they’re not quite as prevailing as they used to be. (Perhaps we could put classic viruses on the shelf with Author and Dickens.)
These days, in the modern era, viruses are acknowledged to spread through vulnerabilities in web browsers, files shared over the internet, emails themselves, and computer networks.
As far as web browsers are concerned, Microsoft’s Computer network Adventurer takes most of the heat for spreading viruses because it’s used by more folk for web surfboarding than any another browser.
Nevertheless, “Any web browser possibly
has vulnerabilities,” Nachenberg said.
For instance, let’s say you go to a website in IE you have every reason to think is safe, Nachenberg said.
But unluckily it isn’t. It has virus code hidden in its background that IE isn’t protective
you from. Piece you’re looking at the site, the virus is downloaded onto your computer, he said. That’s one way of catching a nasty virus.
During the past two years, another prevailing way to catch a virus has been through downloads computer users share with one another, mostly on music sharing sites, Kuo said. On Limewire or Kazaa, for instance, teenagers or another music enthusiasts mightiness think they’re downloading that latest Justin Timberlake song, once
in reality they’re downloading a virus straight into their computer. It’s easy for a virus writer to put a transfer
with a virus on one of these sites because everyone’s sharing with everyone else anyway.
Here’s one you mightiness not have thought of. If you use Outlook or Outlook Express to send and obtain email, do you have a preview pane below your list of emails that shows the contents of the email you have highlighted? If so, you may be putt yourself at risk.
Some viruses, although a small percentage according to Nachenberg, are inserted straight into emails themselves.
Forget opening the attachment. All you have to do is view the email to possibly
get a virus, Kuo added. For instance, have you ever opened or viewed an email that states it’s “loading”? Well, once everything is “loaded,” a virus in the email mightiness simply load onto your computer.
So if I were you, I’d click on View on the toolbar in your Outlook or Outlook Express and close the preview pane. (You have to click on View and then Layout in Outlook Express.)
On a network at work? You could get a virus that way. Worms are viruses that move into your computer via networks, Kuo said. They travel from machine to machine and, unlike, the classic viruses, they attack the machine itself rather than individual files.
Worms sit in your working memory, or RAM, Nachenberg said.
OK, so we’ve talked simply about how the viruses get into a computer. How do they cause so more damage once they’re there?
Let’s say you’ve caught a classic virus, one that replicates and attacks various files on your computer. Let’s go back to the example of the virus that ab initio infects your Microsoft Word program.
Well, it mightiness eventually cause that program to crash, Nachenberg said. It besides mightiness cause damage to your computer as it looks for new targets to infect.
This process of infecting targets and looking for new ones could eventually use up your computer’s ability to function, he said.
Often the destruction a virus causes is pegged to a certain event or date and time, called a trigger. For instance, a virus could be programmed to lay dormant until Gregorian calendar month 28. Once
that date rolls around, though, it may be programmed to do thing
as innocuous but annoying as splash popups on your screen, or thing
as severe as reformat your computer’s hard drive, Nachenberg said.
There are another potential reasons, though, for a virus to cause your computer to be acting slow or in weird ways. And that leads us to a new segment – the reason virus writers would-be want to waste their time creating viruses in the 1st place.
The majority of viruses are still written by teenagers looking for several notoriety, Nachenberg said. But a growing segment of the virus-writing population has another intentions in mind.
For these another intentions, we 1st need to explain the “backdoor” concept.
The sole intention of several viruses is to create a vulnerability in your computer. Once it creates this hole of sorts, or backdoor, it signals house to mama or dada virus writer (kind of like in E.T.). Once the virus writer receives the signal, they can use and abuse your computer to their own likings.
Trojans are sometimes used to open backdoors. In fact that is normally their sole purpose, Kuo said.
Trojans are pieces of code you mightiness transfer
onto your computer, say, from a newsgroup. As in the Trojan War they are named after, they are normally disguised as innocuous pieces of code. But Trojans aren’t considered viruses because they don’t replicate.
Now back to the real viruses. Let’s say we have Joe Schmuck virus writer. He sends out a virus that ends up infecting a thousand machines. But he doesn’t want the feds on his case. So he instructs the viruses on the various machines to send their signals, not of course to his computer, but to a place that can’t be traced. Hotmail email happens to be an example of one such place, Kuo said.
OK, so the virus writers now control these computers. What wish they use them for?
One use is to send spam. Once that backdoor is open, they bounce spam off of those computers and send it to another machines, Nachenberg said.
That’s right. Several spam you have in your email right now may have been originally sent to another innocent computers before it came to yours so that it could remain in disguise. If the authorities could track down the innovational senders of spam, they could crack down on spam itself. Spam senders don’t want that.
Ever detected
of phishing emails? Those are the ones that purport to be from your computer network service provider or bank. They typically request several information from you, like your credit card number. The problem is, they’re NOT from your computer network service provider or your bank. They’re from evil folk after your credit card number! Well, these emails are often sent the same way spam is sent, by causing them via innocent computers.
Of course makers of anti-virus software system use a variety of methods to combat the onslaught of viruses. Norton, for instance, uses name scanning, Nachenberg said.
Signature scanning is similar to the process of looking for DNA fingerprints, he said. Norton examines programming code to find what viruses are ready-made of. It adds those bad manual it finds to its large information of another bad code. Then it uses this huge information to seek out and match the code in it with similar code in your computer. Once
it finds such virus code, it lets you know!
©2004 by Kara Glover
Simply simply about the author:
Kara Glover is a Computer Tutor and Troubleshooter.
You can find her articles and tutorials on topics such as
Microsoft Word®, Excel®, and PowerPoint® on her website: http://www.karathecomputertutor.com
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