Step 2: Use and update anti-virus software

Use anti-virus software to prevent viruses from damaging your computer.

Anti-virus software helps prevent infections from a wide range of malicious software (also called malware). Malware can be transmitted by downloading infected programs from websites or clicking on a web link in an email.

Computer malware is a serious threat. It can:

• steal your passwords or other personal information
• allow a criminal to take control over your computer in support of other criminal activities
• allow a criminal to impersonate you online, resulting in theft of your identity and fraud
• slow down your computer
• corrupt or destroy files
• delete files, and/or
• automatically forward the virus to other computers without your knowledge.

Fortunately there is effective anti-virus software available that checks for and removes most computer viruses and can protect your computer from being infected by viruses.

How to install and use anti-virus software

• Install and activate anti-virus software on your computer. Most computers bought in the last few years have trial anti-virus software already installed on them.
  

  If you don’t have any anti-virus software on your computer you can:

  • select and install a commercial product of your choice, or
  • select a free for non-commercial use software product listed on AusCERT’s guide Protecting your computer from malicious code.

Some free products are as good as commercial products or better. It is better to have up-to-date free anti-virus software than expired commercial software that has passed its licence period, or no anti-virus software at all. Make sure your anti-virus software is always turned on and set to scan incoming and outgoing email. When the subscription is due, renew your anti-virus software or replace it with a similar product. For more details advice, please see the factsheet on free security software for non-commercial use.

• Set your security software to automatically update. New viruses are circulated on the internet regularly, so it is important that you anti-virus software is up-to-date.

  Most of the well-known anti-virus software can be set to automatically check the vendor's website for updates to the anti-virus software. It can install updates on the computer immediately or at your nominated time. Activating the automatic update feature will ensure you remain protected.

• Check your computer is not already infected with a virus. If it is infected, remove the virus. To check if your computer is infected with a virus and remove it, run your anti-virus software and follow your instructions. You should run your anti-virus software at least once a week. For more detailed advice, please see the three factsheets which explain how to detect malware on your computer.
• Install anti-spyware software, a firewall and an anti-spam filter. This will ensure that you are protected against viruses, spyware and hackers.
• Be smart about using the internet to prevent viruses.
  • Do not open email attachments if you do not know the sender.
  • Scan email attachments with anti-virus software before opening them.
  • Only download files from reputable internet sites.
  • Be wary when exchanging files with colleagues or friends.
  • Never click on hyperlinks in emails received from unknown sources.
• Keep yourself informed about latest security threats. Subscribe to email notification services that keep you informed about the latest in security problems and solutions. You can sign up for the free E-security Alert Service from this website.

Alternatively, your anti-virus software vendor may have an email alert system. Look for a 'keep informed' tab or section on the software’s main screen.

Further information

AusCERT's guide Protecting your computer from malicious code provides in depth advice on the steps home internet users and small to medium sized organisations can take to secure their computers and networks.This guide is relevant to those who use Apple Mac, Microsoft Windows XP and Vista operating systems.