All About Computer Viruses
Your computer is as slow as molasses. Your mouse freezes every 15 minutes, and that Microsoft Word program just won’t seem to open.
You might 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 make copies of themselves, or replicate, inside your computer without asking your explicit written permission to do so. Forget getting your permission down on paper. Viruses don’t bother to seek your permission at all! Very invasive.
In comparison, there are pieces of code that might replicate inside your computer, say something your IT guy thinks you need. But the code spreads, perhaps throughout your office network, with your consent (or at least your IT guy’s consent). These types of replicating code are called agents, said 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 about the good guys, or the agents. We’ll be talking 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 perhaps 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 other files. These could be other random files on your hard drive, the files furthest away from your Microsoft Word program, or other files, depending on how the virus writer wanted the virus to behave.
This virus code could contain hundreds or thousands of instructions. When it replicates it inserts those instructions, into the files it infects, said Carey Nachenberg, Chief Architect at Symantec Research Labs, an arm of anti-virus software-maker Symantec. Corp.
Because so many other types of viruses exist now, the kind just described is called a classic virus. Classic viruses still exist but they’re not quite as prevalent as they used to be. (Perhaps we could put classic viruses on the shelf with Hemingway and Dickens.)
These days, in the modern era, viruses are known 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 Internet Explorer takes most of the heat for spreading viruses because it’s used by more people for web surfing than any other browser.
Nevertheless, “Any web browser potentially 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 unfortunately it isn’t. It has virus code hidden in its background that IE isn’t protecting you from. While 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 prevalent 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 other music enthusiasts might think they’re downloading that latest Justin Timberlake song, when in reality they’re downloading a virus straight into their computer. It’s easy for a virus writer to put a download with a virus on one of these sites because everyone’s sharing with everyone else anyway.
Here’s one you might not have thought of. If you use Outlook or Outlook Express to send and receive 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 putting yourself at risk.
Some viruses, though 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 potentially 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 might just 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 come 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 about how the viruses get into a computer. How do they cause so much 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 initially infects your Microsoft Word program.
Well, it might eventually cause that program to crash, Nachenberg said. It also might 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 January 28. When that date rolls around, though, it may be programmed to do something as innocuous but annoying as splash popups on your screen, or something as severe as reformat your computer’s hard drive, Nachenberg said.
There are other 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 want to waste their time creating viruses in the first place.
The majority of viruses are still written by teenagers looking for some notoriety, Nachenberg said. But a growing segment of the virus-writing population has other intentions in mind.
For these other intentions, we first need to explain the “backdoor” concept.
The sole purpose of some viruses is to create a vulnerability in your computer. Once it creates this hole of sorts, or backdoor, it signals home 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 usually their sole purpose, Kuo said.
Trojans are pieces of code you might download onto your computer, say, from a newsgroup. As in the Trojan War they are named after, they are usually 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 Shmo 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 will 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 other machines, Nachenberg said.
That’s right. Some spam you have in your email right now may have been originally sent to other innocent computers before it came to yours so that it could remain in disguise. If the authorities could track down the original senders of spam, they could crack down on spam itself. Spam senders don’t want that.
Ever heard of phishing emails? Those are the ones that purport to be from your internet service provider or bank. They typically request some information from you, like your credit card number. The problem is, they’re NOT from your internet service provider or your bank. They’re from evil people after your credit card number! Well, these emails are often sent the same way spam is sent, by sending them via innocent computers.
Of course makers of anti-virus software use a variety of methods to combat the onslaught of viruses. Norton, for instance, uses signature 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 made of. It adds those bad instructions it finds to its large database of other bad code. Then it uses this vast database to seek out and match the code in it with similar code in your computer. When it finds such virus code, it lets you know!
©2004 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 know where it appeared: kara333@earthlink.net
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
kara333@earthlink.net
Written by: Kara Glover
NAVIGATION
10 Easy Steps to Speed Up Your Computer Without Upgrading
10 Power Tips for Presentations with Computer Projection
10 PROVEN TIPS TO SURVIVE A COMPUTER CRASH
10 Secrets To A Healthy Computer And A Happier You
10 Tips on Computer Clutter Clean Up
14 Household Ways To Protect Your Computer From Viruses
3 Simple Ways To Save A Bunch Of Money When Buying A New Computer
3 Summer Computer Tips
30 Secrets Of A Good Computer Lesson
4 Computer Money saving Tips
5 Critical Steps to Protecting Your Computer on the Internet
5 Simple Ways To Increase Your Computer Speed
5 Stress Reducing Computer Tips
5 Sure Fire Tips for Buying a New Computer
5 Tips For Buying The Right Laptop Computer
5 Tips to Color Code Your Way from Computer Chaos to Coherence
5 Ways To Make Night And Weekend Computer Life Rich
5th generation Computers Corporate infrastructure
6 Essential Steps to Protect Your Computer On the Internet For Free
6 tips for Keeping Aurora Away from your computer and 1 tip to Fix it if Aurora has Gotten You
7 Barebones Computer Buying Tips
A Guide to Computer Desks
A Hacker Inside Your Computer
A Look at Computer Desks for Children
Advancement in Computer Technology
Adware Are Your Business s Computers Secure
An eBay Computer Purchase
Are cyber criminals phishing your identity from your computer
Are You At The Mercy Of Computer Geeks
Are You Being Mislead By Your Current Computer Dealer
Are You Making Any Money With Your Computer Yet
Are You Saving Money With a Computer Support Plan
Avoiding Spam Scams and Computer Viruses
Back that Thang UP Insure the Data on Your Computer
Basic Computer Thermodynamics
Be Prepared in the Event Computer Disaster Strikes
Beat The Bugs Helpful Links That May Help You Combat Annoying Computer Viruses
Becoming a Computer Trainer
Beeps Your computer is telling you something
Broadcasting Mp3 Audio Via Computer The Looney Tune World Of Podcasting
Build your first computer from hardware scratches
Build Your Own Computer
Build Your Own Computer or Buy
Build Your Own Computer What to Look for in a Case
Buy a home through your home computer
Buying a computer Ask these 3 questions
Buying a Used Laptop Computer
Buying computers at a discount with peace of mind
Buying DDR memory for your computer
Buying Guide for Laptops Personal Computers Notebooks
Buying the Perfect Computer The FIRST Time
Career Track Computer Programmer
Career Track Computer Software Engineers
Choosing a Laptop Computer Based on Hardware and Software Needs
Classification of Computers
Combat Computer Spyware An AntiSpyware Program Isn t Enough
Computer Aided Design Contracting Tax Concerns In The UK
COMPUTER BACKUPS
Computer Business Opportunity Provide Huge Profit Potential
Computer Buying Advice For Novices
Computer Career
Computer Case Modding
Computer Cases The Basics
Computer Certification Anticipation vs Nervousness
Computer Certification Become A Utility Player
Computer Cleaning
Computer Cleaning May Be The Best Home Based Part time or Full time Business
Computer Components for Idiots
Computer Consulting 101 Hiring Tips Part 1 of 2
Computer Consulting Profit Secrets
Computer Controlled LED Signs
COMPUTER COURTESY
Computer Data Backup Data Backup Solution Will Give You A Peace Of Mind
Computer Data Backups Test Now or Cry Later
Computer Data Recovery Options
Computer Disposal Throwing Away Your Computer Money and Idenity
Computer Do s and Don ts
Computer Equipment Disposals and Recycling
Computer Geeks and Garden Gnomes
Computer Graphics They re Not All The Same
Computer Hacks Quacks Looking for Cracks
Computer Hardware Preventive Maintenance Software
Computer Help Desk Stupid Questions brought to you by Computer Service Now CSN
Computer Homeschooling the added advantage in african american children s education Part 1
Computer Hygiene Take Out The Trash
Computer In The Shop What Do You Do Now
Computer Insurance
Computer Loans An opportunity to have a computer of your own
Computer Loans Become Techno Savvy the Easier Way
Computer Maintenance and Improving PC Performance
Computer Monitor Buying Guide
Computer Network Designing
Computer Network Installation
Computer Profits From Home What s Right for You
Computer Rental Worth Your Money
Computer Rentals The Best Classroom Computer Training Solution
Computer Running Slow Here s One Reason
Computer Security What Exactly Is It
Computer software Excellent prices
Computer Software Genres That Help Students Think
Computer SOS Inc Release of Upgraded League Management Software Package
Computer Support London Network Support London Network Installation London
Computer Tips that Help Small Businesses Operate Profitably
Computer Traumas
COMPUTER VIRUS THREATENS MY HOME BUSINESS
Computer Virus Writer s A Few Bats In The Belfry
Computer Viruses are Bad Luck
Computer Viruses Worms and Hoaxes
Computers and Internet Inspiring Us to Create
Computers and Web Cams are Taking Communication to Levels Only Imagined in Sci Fi Novels
Computers Are Not Scary
Computers are Running My Life
Computers Freedom and Privacy
Computers Introverts and the Information Age
Computers You CAN Master Any Program
Coping with a Serious Data Loss from your Computer Hard Drive
Corporate infrastructure for Fifth generation Computers
Corporate Promotional Gifts The Fridge Magnet Is Dead Long Live the Computer Desktop
Countering the Spread of Spyware on your Computer
D BUST Your Computer Part 1 Instructions for Microsoft Users
D BUST Your Computer Part 2 for Microsoft users
D BUST Your Computer Part 3 for Microsoft users
D BUST Your Computer Part 4 a for Microsoft users
D BUST Your Computer Part 4 b
D BUST Your Computer Part 4 c
D BUST Your Computer Part 4 d
D BUST Your Computer Part 5
Definitions for Computer Modding and Form Factor
Dell Computer Corporation Recall of Latitude Inspiron Laptop AC Adapters
Detecting and Eliminating Computer Viruses at the Gateway
Did You Ever Want to Completely Erase Everything on Your Computer
Different Categories of Computer Games
Dirty Little Computer Viruses and How To Protect Yourself
Distance Learning and Elearning for Computer Techs
Do The Media Spread Computer Viruses
Do You Feel Used by Computers
Do You Know How To Remove Spyware From Your Computer
Do you know who is snooping around your computer right now
Do you need computer training
Dual core computer processors luxury or necessity
Dusting Your Computer Keeping it Cool
Expansion Slots Cards and Bays Choosing the right computer case
Extending the Life of Your Business or Personal Computer Printer
Finally An Understandable Introduction To Computers
Five Simple Steps to Speed up Your Computer
Focus On White Collar Crime Accounting Fraud and Computer Crimes Creates Need For Qualified Investigators
Gaming Computers and Computer Modding
Get Ahead When You Build Your Own Computer
Get Started in Computer Game Creation
Get Valuable Computer Based Training Online FREE
Getting Started In Information Technology Computer Consulting
Good News Bad News of Computer Security from a Keen Non Techie
Guide on How to Land Computer Jobs
Hackers Given Access to IRS Computers
Hardware for Computer Desks
Have You Invited A Spy Into Your Computer
Healthy Webmasters Choose Ergonomic Computer Products
Heliodisplay Computer Video With No Screen
Help Keep the Computers on Earth Clean and Healthy
Help Keep The Computers On Earth Clean And Healthy Protect Your Techno Friends From Viruses And Sickness
Help My Computer s Being Invaded
Help There s an Intruder in my Computer
Hidden information is stored on your computer about every url you ever visit
Home Computer Desks A Variety of Options
Home Office Tip 2 Computer Health Hazards
How a Computer Consulting Business Can Help Your Company
How Much Money would it cost you to regain the use of your computer after a serious virus infection
How Protected are You Safeguard Your Small Business from Computer Viruses
How Safe is Your Critical Business Data on Your Computer System
How Spyware Blaster Can Protect Your Computer From Harm
How to backup your computer data
How to Backup Your Computer Files
How to Become a Computer Consultant
How To Buy The Right Computer
How to choose a new hard drive for your computer
How to choose your computer
How To Deal With Computer Problems
How to Get a FREE Computer Scale Printer from DHL
HOW TO GET THE COMPUTER YOU WANT WITHOUT SPENDING A FORTUNE
How to Have Your Computer Cake and Keep Your Family Too
How To Keep Your Computer Virus Free
How To Optimize Your Online Time Through Efficient Computer Use
How to Prevent Computer Security Risk and How to Keep Your Small Business Safe
How To Prevent Spyware Attacking Your Computer
How To Recognize If Your Computer Has A Virus Or Trojan On It
How to reduce Computer problems
How to safeguard your computer
How To Save Big Bucks On A Laptop Computer
How To Stop The 1 Cause Of Computer Slow Downs And Crashes
How To Take Care Of Your Laptop Computer
How To Take Good Care Of Your Computer Even If You Are A Clueless Newbie
How To Work At Home Using Your Computer Even If You Can t Type
How Viruses and Spyware Get In to your computer
HR MANAGERS USE COMPUTER FORENSICS TO INVESTIGATE EMPLOYEE ALLEGATIONS
Hurricanes Wilma Katrina And Rita Force Businesses To Rethink Computer
I Spy Something Terribly Wrong In Your Computer
If You Had Problems in the Past with a Computer Virus Then You ll Want to Know How Easy it is to Setup Firewall Protection
Image conversion In Computers
Important Steps to Protect your Computer from Hurricanes
In Computer Memory what is CAS Latency
Is DVD Storage An Attractive Alternative For Your Computer Backup
Is Spyware Slowing Your Computer Down To A Crawl
Is your Computer a friend or a Dirty Name
Is your Computer Infected with Spyware
Is Your Computer Sick
Is Your Computer Slow and Sluggish Take These Steps To Speed It Up
Is Your Computer Strong Enough For A work From Home Internet Business
Jobs Online How To Get Your Computer to Work For YOU
Keep A Diary Of Your Computer
Keep Computer Training Simple Please
Keeping your Computer Spyware Free for Free
Laptop Computer Extras for the Mobile Traveler
Laptop Computers and the PVP Effect
LCD Touch Screen Computer Monitor
Learn How To Hide Files and Folders On Your Computer
Learning Math and Dosage Calculations Using a Computer Program
Local Company gains Four Nominations in Computer Trade Oscars
Make a place for computers in children s world
make alot of mney using ur computer
Make your computer read selected text from any application with a single keystroke
Make Your Fortune in Computer Services
Make your own Computer Software without Programming
MCSE CCNA How To Choose A Computer Certification
More Computer Consulting 101 Hiring Tips Part 2 of 2
My Computer is Making a Strange Noise
My dad listens to music all day on his computer
Newbie Of course you can make money working from home on your computer
No Computer Sound
Notebook or Desktop Computer Which Should You Choose
One Way to Solve Memory Problems with your Computer
Optimize Your Computer For Peak Performance
Organization Tips How to Organise Your Computer Files
Organizing Your Desktop Computer Desktop That Is
Paranoia or Are Public Internet Computers Dangerous
Performance Computer Chips For Cars And Trucks
physical topology of a network refers to the configuration of cables computers
Preventing Malicious Spyware or Adware from Hijacking Your Computer
Protect and Secure Your Computer Life
Protect Your Computer
Protect your Computer and Internet Privacy
Protect Your Computer and Your Business
Protect Your Computer And Your Personal Information From Spyware
Protect Your Computer System With A Comprehensive Security Policy
Protecting Your Computer from Adware and Spyware
Quick Guide to Computer Training
Rackmount Computer Keyboards
Rackmount Computer Monitors Provide Dependability
Read Chinese Online How To Configure Your Computer To Display Chinese Characters
Real Estate Records In The Computer Age
Refurbished Computers on the Internet
Reinstall Windows XP On Your Computer
Removing Bargain Buddy Adware from your Computer
Reviving Old Computer Games
Secrets to SpyProofing Your Computer In Four Easy Steps
Secure Your Data Windows Data Backup Computer Software
Securing your Computer to Keep Up with Internet Threats
Security necessities to prevent your computer from Spyware
See How To Revive A Dead Computer
Setting up Your New Computer How To Move Your Old Files to Your New Computer
Should You Buy A Cheap Computer Desk
Some Computer Forensics Basics
Speed Up Your Computer Inner cleansing tips for your pc
Spyware Protection A Must for Any Home Computer
Starting A Home Computer Business Is Still Smart
Success at Work Techniques Computer Literacy
Survival Without Computers
Ten Great Careers For Computer Geeks
The ABCs Of Computer Memory
The Benifits of Assembling Your Own Computer
The Charm of an Oak Computer Desk
The Complete Guide To Spotting Computer Spies Recording Devices
The Computer Friendly Resume
The computer virus that could take advantage of you
The Cost of Spyware on your Computer
The Evolution of Technology The History of Computers
The Flexibility of Roll Top Computer Desks
The Future Of Computer Certification Exams
The Great Underutilized Computer
The Hidden Benefit Of Computer Certifications
The History Of Laptop Computers
The Need for Rackmount Computer Cases
The Newbie s Guide to Personal Computer Maintenance
The Secret Computer Virus That is Virtually Undetectable
The Single Least Expensive Yet Most Valuable Way to Upgrade Your Computer s Performance
The Top Twelve Threats No Computer User Should Ignore by Kai Chandler
The Trials and Tribulations of A Confused Computer
The Trials and Tribulations Of Learning A New Computer Skill
Thinking about earning your computer degree online
Three Things You Can Do to Keep Your Computer Running at Maximum Performance
Tips for Buying a First Computer
Tips For Finding Great Deals On Computer Accessories Supplies
Tips For the Late Blooming Computer User
Top 10 things everyone must know about computer viruses
Top 10 Ways to Protect Yourself from Computer Viruses
Transfer The Digital Camera Images To Your Computer
Twelve Things You Should Know to Save on Computer Software
Twelve Threats No Computer User Should Ignore
Types of computer infections
Ultimate Checklist On How To Revive A Dead Computer
Understanding Computer Memory
Understanding the Software Layers of a Computer
Unleash The Dragon Inside Your Computer
Update your computer system with bad credit computer financing
Use Internet Resources To Get Rid Of Computer Viruses
Use Your Computer For Your Entertainment Needs
User Friendliness Do Computers Have to be Clinical and Boring
WARNING Do not buy a computer until you read this
Watch Out For eBay Automobile And Computer Scams
Watch out for spyware programs that slow down your computer system
Watch Out For Spyware Programs That Slows Down Your Computer System
What are Rackmount Computers
What is a Protocol the communications between computers on a network
What Is Computer Programming Anyway
WHAT IS SPYWARE AND HOW DO I REMOVE IT FROM MY COMPUTER
What Paper or Computer Files Should You Keep
What s in a Computer Name
What to look for in a Computer Classroom Rental
When to rent a laptop computer
Which Notebook Computer Has Your Name On It
Who s Peering Into Your Computer
Why Build Your Own Gaming Computer
WHY CONSULTANTS DON T TELL ABOUT COMPUTER SECURITY
Why Do I Need Anti Virus Software For My Computer
Why More Women Should Consider a Career in Computer Programming
Wireless The new trend in Computer Rentals and Projector Rentals
Work A Home Computer Jobs Are Plentiful
Work At Home Computer Jobs Can Give You Freedom
Work From Home Using Computer
You Can Stop Computer Viruses
You Voice On Your Own Computer
Your Affiliate Business Peripherals Software Computers
Your Computer Can t Keep Time
Your Computer May Be Infected Here s how to check
Your Computer May Be Infected Here s How To Check NOT about virus
YOUR PRIVACY EXPOSED Computer Forensics International uncovers secrets about recycled hard drives
Zen and the Art of Buying Computer Parts
|