Make sure you're checking for infection
In today's connected world it's easy to fall victim to a virus. There are, however, ways to avoid viral infection:
Install Anti-Virus Software
Anti-virus software is the best way to combat attack. There are two types available, generic virus-detection software and scanning software.
Scanning software is the most common. It checks your system for known viruses, examines incoming files and warns of infection. When choosing scanning software, look for:
Generic virus-detection software monitors your system for behaviour common to viruses and checks programs and files for modifications. This type of software can even pick up on previously unknown viruses.
A Behavioural Guard, for example, searches for viruses according to the sequence of their actions, rather than their unique code. An Integrity Checker checks files, folders and disk sectors for signs of infection. These programs are, however, prone to false alarms as some valid activities look like viruses in action.
Your anti-virus software is your main defence, so get the best you can afford. To get an idea of what's out there, here's a review of some of the most popular anti-virus products available.
Use your Virus Scanning Software Properly
Once you've installed your anti-virus software check that it's configured to give you the best protection. Make sure it's set to scan all files. Also let it create a recovery or reference disk if it offers to. These disks may be your only hope of recovering from an infection.
Installing virus scanning software is not enough; you need to use it. If you're loading it for the first time, scan your entire system so you start out fresh. Then make a habit of regularly scanning your files, or set your software to do it for you.
Remember that there are new viruses released every day, so you need to keep your software current. Make a habit of collecting updates from your vendor's website, or if your software permits, automate the process.
Subscribe to a variety of virus notification services, as some vendors release warnings earlier than others. You can also subscribe to Microsoft's security bulletin mailing list.
Download Relevant Software Patches
Some viruses attack weaknesses in software. Software vendors are naturally on the look out for such attacks, and release patches to deal with them, usually on their websites. The latest security updates for Microsoft Outlook, for example, are available on the Microsoft website for download.
Turn Off the Microsoft Windows Scripting Host
Some viruses are written to exploit the vulnerabilities in Windows' Visual Basic scripting. The ILOVEYOU virus, for example, contains an attachment that ends .vbs, the suffix for Visual Basic files. Once you click on the file you become infected.
Turning off Windows Scripting Host is an effective anti virus measure, and will help prevent you from executing such files. Here's how:
Always Scan your Removeable Media
Make sure that all floppy disks, CD-Roms, Zip and other disks are scanned before you use them. When it comes to floppy disks, this can help avoid boot sector viruses.
Be Wary of Viruses in Email Attachments and Html Content
Many viruses spread via email, so it's wise to develop safe practices.
Avoid attachments you're not expecting, even messages from those you trust, because many viruses and worms infect victims' address books without their knowledge. If you're determined to open the attachment, it's worthwhile checking with the sender first.
As a rule scan all incoming attachments for viruses before you open them. Also check for file types that commonly carry viruses, like those ending .doc, .com, .exe. If you're in doubt, rather be over-cautious and delete any files you don't trust.
Take Care when Downloading Files
Make sure that you download files from a reputable source. Upgrading Microsoft Internet Explorer from the Microsoft site, for example, is fine, but downloading files from sources like newsgroups and warez sites is not a good idea. Ensure that your anti-virus software is set up to scan all files you download.
Only Allow Essential Software Onto your Systems
Installing unnecessary software can act as a gateway for a virus, so restrict the software that is allowed to be installed on your systems.
Make Regular Back-Ups
This may not be a way to prevent viruses, but creating regular back-ups can save hours, even days of work if you become infected.
Educate your Employees
Make sure that your employees are aware of the threats posed by viruses and malicious code. Take some time to educate them about the procedures to follow to keep your systems clean. Once everyone is aware of the precautions they should take, you stand an excellent chance of avoiding infection.
For more information, read about how viruses work.