Basic Virus Guide
by Scott
What is a computer virus?
A computer virus is a malicious program that mutates or attaches itself to other trusted programs, also know as infecting the program. An infected program behaves in a similar manner spreading the computer virus even further. Many computer viruses have destructive behaviors such as erasing or corrupting data which can cause frequent error messages, program freezes, computer crashes or loss of important documents. Others may simply annoy you with strange or silly popup messages or waste valuable resources.
Computer viruses typically spread between computers through infected files or programs shared via CD, floppy disk, DVD, USB key (thumb drive) and through email.
Do I need to worry?
Yes.
Every single computer is vulnerable to computer viruses. Therefore every computer user must take steps to protect their computer and data. Unknowingly passing a virus along to a customer or business partner can damage their relations and trust they hold with you. If everyone took the appropriate measures to protect themselves, computer viruses would not spread nearly as fast as they do.
How do I know if I have a computer virus?
This is a tough question. There is no clear sign of a computer virus because all viruses do not behave the same. Here are a few common symptoms of an infected computer.
- Your computer is running slower than normal
- Your computer restarts with out you telling it to
- Your computer freeze or has periodic pauses where it stops responding
- You receive frequent error messages
- You notice your documents are being deleted without your consent
Some viruses are active the instant they enter a computer while others may lay dormant for a while and then become active after computer restart, when an infected program is run, or even on a specific date or time.
How can I detect and eliminate computer viruses?
The best way to find out if a computer is infected with a virus is to run a virus scan. If you have an antivirus application installed on your computer you can use the built in scanner, however I would also recommend scanning your computer about twice a month using a free online or downloadable virus scan tool from a company other than the one that produced your antivirus software. Not every virus scanning application is 100% perfect and none of them are exactly the same. Scanning with multiple tools will increase your chances of wiping your computer free of computer viruses.
Below is a list of free online and downloadable virus scanning tools. These tools are for scanning and removing current viruses only and do not provide protection from future infections. These tools are generally pretty simple to run, but if you need assistance please read "How to detect and remove computer viruses".
Online scanning tools
- Trend Micro Housecall: Scans and removes viruses and spyware, most all browsers supported.
- Panda ActiveScan: Scan for viruses, spyware and malware, removes viruses, Internet Explorer required, ActiveX plug-in.
- McAfee Free Scan: Scans for viruses and links to info on how to remove them, Internet Explorer required, ActiveX plug-in.
- Symantec Security Check: Scan for viruses and security threats, Internet Explorer required, ActiveX plug-in.
- Microsoft Windows Live Protection Center: Scan for viruses and security threats, Internet Explorer 6.0+ required.
Downloadable virus scanning tools
- McAfee AVERT Stinger: A stand-alone utility used to detect and remove specific viruses.
- Avast! Virus Cleaner: A stand-alone utility used to detect and remove specific viruses.
- Microsoft Malicious Software Removal Tool: Checks and removes infections by specific, prevalent malicious software.
- Symantec Removal Tools: Small downloadable tools to remove specific viruses, if you know the name of the virus you're infected with.
- McAfee Removal Tools: Small downloadable tools to remove specific viruses if you know the name of the virus you're infected with.
- Kaspersky Removal Tools: Small downloadable tools to remove specific viruses if you know the name of the virus you're infected with.
- F-Secure Removal Tools: Small downloadable tools to remove specific viruses if you know the name of the virus you're infected with.
How can I protect myself from computer viruses?
There are a number of things you can do to protect yourself from computer viruses, one of the most important things is to keep your operating system, Web browser and other software applications up to date. You also need an antivirus application installed on every computer.
Microsoft Windows Update
If you use Microsoft Windows you should visit http://update.microsoft.com at least once a month to receive all critical updates at a minimum. Or, if you don't think you will remember to visit the Windows Update website, you should turn on Microsoft's Automatic Updates feature. You can set it to notify you when updates are available or even install them automatically.
Keep your Web browser up to date
Keep your Web browser up to date with the latest version and also with the latest security patches. If you use Internet Explorer the Microsoft Windows Update website will take care of this for you. If you use Firefox, Opera or another Web browser you should visit the manufactures website to get the latest version. You should also read their security section to find out what other features are available to you.
Keep your software up to date
For users of the Microsoft's Office application suite there is a separate Office Update website. You should visit the Microsoft Office Update site at least once a month to receive any critical updates. For all other applications, especially ones that access the internet, look for a "Check for Updates" menu item under the Tools or Help menu or visit the manufactures website.
Install an antivirus program and keep it up to date
Antivirus software (virus scanner) is another very import tool for protecting yourself from computer viruses. Antivirus software helps to detect viruses and remove them before they cause any damage to your computer. Every computer you own should have up-to-date antivirus software installed. Most antivirus software have automatic update features so you remain protected against the latest threats without having to think about it (internet connection required). Be sure you have this feature turned on at all times. Antivirus applications typically come with one 1 year update subscription, when this subscription runs out you must purchase new software or renew your subscription to remain protected from the latest threats.
Online orders from the manufacturers website typically give you on option to have your subscription automatically renewed when your current one runs out. Choosing this option frees you from having to remember, however you have to remember to cancel if you decide to switch programs when your subscription ends.
Below is a list of some of the best know and trusted antivirus applications.
note: It's important to note only one antivirus application should be installed on your computer at a time. The scanning tools listed above are independent scanners that only run when you tell them to and are therefore ok to use along side your antivirus software.
- Free Avast! Home Edition: Protection from computer viruses for free! (antivirus)
- AVG Anti-Virus Free: Protection from computer viruses free! (antivirus)
- McAfee VirusScan Plus: Protection from computer viruses, hackers, and spyware (antivirus, firewall, antispyware).
- Symantec Norton Antivirus: Protection from computer viruses and spyware. (antivirus, antispyware)
- Panda Antivirus: Protection from computer viruses and spyware. (antivirus, antispyware)
- ZoneAlarm Antivirus: Protection from computer viruses and hackers. (antivirus, firewall)
- Trend Micro AntiVirus: Protection from computer viruses and spyware. (antivirus, antispyware)
Even with these protections in place your computer could still become infected with a computer virus. Be smart about your computing habits. Don't open any email attachments from unknown senders and avoid opening attachments from people you know if you were not expecting them.
Be careful which websites you visit. Websites with pornographic or illegal content are commonly used to spread viruses. An un-patched Web browser or operating system as well as an un-suspecting user can bean easy target.