Protect Your Computers against Viruses

Virus software installed on each computer in the network is a little more controversial. Virus software tends to be more or less intrusive. Some anti-virus software will constantly monitor all files. However, users tend to complain about reduced performance as the hard disk gets scanned.

Other software will only scan when you tell it to, but such software is of little use in practice in my opinion. No-one will scan nearly as often as required.

If you use anti-virus software, be sure to update the virus database definitions frequently. Some anti-virus scanners will do this automatically if they have a fixed line to the Internet. You should update at least daily to be reasonably protected. New viruses typically spread the most within the first couple of days.

Virus scanners will only do part of the job, though. New viruses constantly show up, and no matter how clever the anti-virus software is, it probably won't recognize most new viruses.

It is important to keep updating your application programs with new patches and service packs as they become available. This is especially important with Microsoft products. Not necessarily because Microsoft software is any buggier than other programs, but because Microsoft programs are widely used. That makes them popular with the virus makers who use bugs in them to spread viruses. In fact, one way to avoid viruses is to use alternatives to Microsoft products whenever possible (of course, that may introduce other problems instead).

Some viruses use bugs and security flaws in Internet Explorer to spread. By default Internet Explorer is configured in a way that is relatively unsafe. By selecting Internet Options from within Internet Explorer and then clicking on the Security tab, you can change the security settings.

In the so called "Internet Zone", a security setting of High is really warranted. Unfortunately, that will make it impossible to view certain content - especially Adobe Acrobat documents. I have modified my settings so that I get prompted whenever Internet Explorer wants to do anything potentially dangerous. If I know I am trying to read an Adobe document I click yes, otherwise I click no. I get quite a lot of prompts, though and it is a bit annoying.

The thing about Internet Explorer is that it is used not only when you are browsing the Internet, but also when you receive an e-mail containing HTML or links to HTML content. It is possible to send an e-mail that will automatically download and run a virus when you open it. Tightened security settings could help you out here.

Macro viruses are most common in Microsoft Office documents. Again, this is not because Microsoft Office is the only software that can be infected but because everyone is using it. You can make Office warn you about documents containing macros. It is good practice to do that, although many users will just ignore the warnings as they can become to frequent.

The final advice is to install launch protection software on every computer. It will not protect you against macro viruses, but you will be safe from most other types. The combination of launch protection and a good anti-virus scanner in the mail server provides pretty good protection.