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 Avoiding Virus Infections, Adware and Spyware.... |
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What is a virus?
A virus is a program or piece of code that is loaded onto your computer without your knowledge and runs against your wishes.
Viruses are manmade and can replicate themselves.
A simple virus that can make a copy of itself over and over again is relatively easy to produce. Even such a simple virus is dangerous because it will quickly use all available memory and eventually bring the system to a halt.
An even more dangerous type of virus is one capable of transmitting itself across networks and bypassing security systems.
Since 1987, when a virus infected ARPANET, a large network used by the Defense Department and many universities, many antivirus programs have become available. These programs periodically check your computer system for the best-known types of viruses.
Some people distinguish between general viruses and worms. A worm is a special type of virus that can replicate itself and use memory, but cannot attach itself to other programs.
Many computer viruses are spreading. In October 2002, there was an outbreak of BugBear, in 2004 Mydoom and Netsky traveled the world, and there are many more. Although anti-virus programs are useful, it is quite possible to remain virus-free, just with a bit of common sense and some knowledge.
Click on the links in the tips below for more explanation.
Tips for working on a Windows computer, virus-free :Strictly adhereing to these rules, you run hardly any risk of getting infected. That makes an anti-virus program almost over kill, although it is never wrong to have a few around. |
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Popular Virus Protection Software...
At Timbertown Web Developers we use NOD32 as our preferred anti-virus software.
NOD32, by Eset, was voted Australian PC User Magazine's Best Antivirus Software for 2001, 2002, 2003, 2004 and 2005. |
It's difficult to go past such a distinguished product.
Listed are some popular virus protection products :
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Install important software updates directly from the Microsoft Update website...
If your operating system is Windows XP, you can download and install security updates automatically from the Microsoft Updates website.
To setup automatic updates click Start / Control Panel / Automatic Updates.
Set your preferences for receiving updates, the click Apply / Ok. |
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Set your browser security to high...
To raise the browsing security level in Internet Explorer :- On the Internet Explorer Tools menu, click Internet Options;
- In the Internet Options dialog box, click the Security tab, and then click the Internet icon;
- Under Security level for this zone, move the slider to High. This sets the security level for all websites you visit to High. (If no slider is visible, click the Default Level button and then move the slider to High.)
Note: Setting the level to high may cause some websites to work incorrectly. If you have difficulty using a website after you change this setting and you are sure the site is safe to use, you can add that site to your list of trusted sites. This will allow the site to work correctly even with the high security setting. |
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Add safe websites to trusted sites...
Designating a website as trusted allows the site to work correctly under the High security setting.
Microsoft strongly recommends that the first website you add to your trusted sites be Microsoft Update (http://update.microsoft.com/microsoftupdate/) so that you can continue to install important software updates directly from the Microsoft Update Website.
To add a website to your list of trusted sites :- On the Internet Explorer Tools menu, click Internet Options;
- In the Internet Options dialog box, click the Security tab;
- Click the Trusted sites icon, and then click the Sites button;
- In the Trusted sites dialog box, enter the website URL in the Add this website to the zone box, and then click Add;
- The Trusted sites feature allows you to restrict trust to only sites that begin with https:. To include sites that begin with http:, including Microsoft Update, clear the Require server verification (https:) for all sites in this zone checkbox;
- Click Ok;
- Under Security level for this zone, move the slider to Medium. This sets the security level for all of the sites that you trust to Medium. (If no slider is visible, click the Default Level button and then move the slider up to Medium.)
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Block pop-up windows in your browser...
A pop-up blocker is a utility that prevents small additional windows from opening when you visit websites. Some websites use these small windows to display helpful information, but many pop-up windows contain advertisements or offensive content.
Malicious attackers also may use pop-up windows disguised as special offers to install malicious code on your computer.
Windows XP SP2 users can take advantage of the Pop-up Blocker built into Internet Explorer. |
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Understand how virus's spread...
Most viruses spread by sending attachments. Such an attachment is a program, which installs the virus, and infects the computer as soon as it is executed (run).
If it isn't run, the computer won't be infected. This means it is not dangerous to receive a virus, nor to save it, look at it, move it, etc., the only thing that is dangerous is to run it.
You can run a program file attachment by (double)-clicking it in an unsafe email program. You can also run a program file by typing its name in a command line and pressing Enter. |
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Make sure that Windows always displays file name extensions...
The file name extension consists of the last letters of the name, usually three of them, which are after the last dot. These letters indicate the file type, for example doc for a Word document, xls for an Excel spreadsheet, exe for an executable program, scr for a script or screensaver, bat for a batch file, pif for a program information file.
Windows' default setting is not to display file name extensions! This is done to make computers easier to use for inexperienced users, but in fact it is outright dangerous, and a serious flaw in Microsoft's design.
It stimulates the spread of worms. It is of the utmost importance to change this setting on every Windows-system right away.
This can be done in the Folder Options, located in Windows Explorer, in a different location in each Windows version. In Windows Millennium Edition the Folder Options are in menu Tools. Select tab "View", and make sure that "Hide file extensions for known file types" is not checked.
Don't work with blinkers on! Know what you are doing!
Note: In other Windows versions the Folder Options may be located elsewhere, e.g. under menu "View" or "File".
It is dangerous not to have extensions displayed, because virus writers reckon with that so they can fool their victims. For example, an infected attachment may be called "story.doc.pif", but it seems to have the name "story.doc". The user, who may have seen that Word documents can have names ending in ".doc" (with a neighbour? at work?) thinks "Hey, that's a Word file", and opens it by double clicking it. But it really is a pif-file (a certain kind of executable control file), and the computer is infected. From then on the virus / worm can do its devastating work, and can infect others too.
Potentially dangerous extensions are exe, com, bat, pif, scr, vb, vbs or cmd. |
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Use a safe email program...
An attachment that is really a worm only becomes dangerous if it is run (executed). Some versions of Outlook (among others) did that already simply by viewing the message in the Preview Pane. Later versions of Outlook (part of Office) and Outlook Express are safe, but it is still important to apply the right patches, so any security holes are fixed in time.
Other email programs having a sound reputation where security is concerned are :To avoid viruses many people now use safe websites Yahoo and Hotmail. |
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Don't execute attachments...
Most email programs let you "open" an attachment by (double)-clicking it. This "opening" means the operating system (Windows) looks up the program that corresponds to the file name extension. Windows then starts that program, and makes it open the attachment as its document.
An appendix that has a name ending in ".xls" is started in Excel, in case of a ".doc" it is Word, etc.
Attachments that are program files are directly executed (run) themselves! If that attachment is a virus (worm), that infects your computer. Safe email programs won't allow that, or at least warn you; unsafe programs sometimes even do it without needing the double-click.
To avoid this risk it is better to open an attachment from someone you know, when you previously agreed it was going to be sent, not from the email program, but in the program that belongs to the file type. So if you receive a file called something.xls, don't double-click it, but save the attachment to a directory on the disk (Eudora does that automatically, in other programs you first press the right mouse button), start Excel yourself, and open the spreadsheet from Excel.
If by any chance the file was not called "something.xls", but rather "something.xls.scr" or "something.xls.exe" or anything, and the Windows setting is wrong so you do not notice that, nothing harmful happens. Excel will simply tell you it cannot open the file, because it doesn't contain a valid speadsheet. |
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Enable Word's macro virus protection...
Sometimes a macro is embedded in a Word document. Macros are a kind of programs, and they could install a virus. Macros can be set to execute automatically, as soon as the containing document is opened in Word.
To avoid this, you must always enable Word's protection against macro viruses, which is present in all Word versions higher than 6. Look for the correct protection option under menu Tools, Options. |
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