I have have Antivirus however I am still getting viruses?

I have Antivirus installed and I make sure that it is constantly up to date however I still have managed to get a Virus. What am I doing wrong?

John, East Maitland

Hi John,

You aren’t doing anything wrong however an up to date antivirus is just one piece of the puzzle.

Antivirus writers and virus writers are locked in a game of cat and mouse. When the antivirus writers detect a new strain of virus they release an update to detect it, when the virus writers find that the antivirus software is now detecting their virus they change it slightly so it is no longer detected.

This is called signature based detection, antivirus writers work out what signature the virus leaves and can then create an update that detects and removes it.

Even with modern day antivirus software selling you on the latest heuristics which they claim can detect viruses before they even know about it, a majority of viruses are still only caught using signature based detection.

So having up to date antivirus software is definitely a major piece of the puzzle.

The next step is ensuring that your computer is up to date. Most viruses are no longer passed through email or infected removable drives, (some still are) they are passed through hacked websites. A hacker will break into a website and inject a special code so that when an unsuspecting user visits the website they get infected.

This special bit of code take advantage of security holes in your software. Keeping your software up to date ensures that when the writers of software find a security hole, you are no longer vulnerable to viruses getting in through that hole.

If you are using Firefox or Chrome browsers they will use Google safe browsing. As Google crawls the web if it detects a website has been hacked it will take note of it. If you then try to access this site in Firefox or Chrome you will get a security warning notifying you that the site may have been hacked and if you proceed you may become infected.

The best way to stay up to date is to use Microsoft Update. This will ensure that your copy of Windows is always up to date. A lot of software will automatically update itself; if you use Firefox or Chrome by default they will automatically update themselves. The other major software to keep up to date in Adobe PDF reader, Adobe Flash and Oracle Java. All of these by default will put an icon in your clock and prompt you to update. Adobe PDF and Flash will be a read box and Java will be an orange box. It is important to let these update when updates are available.

The final piece of the puzzle is being aware of what you are doing. If you are downloading illegal programs and music it is just a matter of time until you get a virus. A lot of illegal downloads contain viruses simply because being a virus writer these days can be a very lucrative career.

I hope this helps you John in better protecting your computer.