Security – malware, spyware, and viruses

Malware is a blanket term for malicious software such as viruses, spyware and other code deliberately designed to stop your computer working properly; delete or corrupt your files; steal information from your computer; or allow others to access your computer and your information.

The consequences of an infection on your computer can be serious, and can include loss of access to your files or even identity theft and fraud.

What are they?

There are many kinds of malware; these are the most common terms you’re likely to see.

Note that while scams, “phishing”, or identity theft aren’t themselves malware, the malware can often be assisting with these criminal activities.


Spyware tracks your actions on your computer and the internet. It “spies” on you in order to collect passwords, track web actions like auto-filled forms with financial and personal data, or even activate webcams or speakers.

It can be disguised as proper software – for example, Trojan software could download and install spyware without you realising it.


A piece of software or code that gets into your computer or applications, replicates itself, and then uses your internet connection to spread itself further. Once installed, they can corrupt your computer or legitimate software, steal and forward data, or fill up your computer until it can’t operate any more.


A piece of software that installs itself and then locks access to your files. When you try to open something, you’ll see a screen that demands payment in some form – often “bitcoin”.

While paying the ransomware can sometimes get your access back, it can happen again unless you fix the core issue, it may not always work, and the ransom can be quite a lot of money.


A piece of software that looks harmless until you download and install it. Once installed, it can perform any amount of harmful tasks. Trojan packages can carry viruses, spyware, or other types of malware.

How do these get on my computer?

Your computer can be infected in many ways, including:

  • Clicking on legitimate-looking website links that turn out to be false
  • Visiting websites that have been infected by malware
  • Downloading infected apps and files from the Internet
  • Opening infected email attachments
  • Social media messages at random with links
  • SMS messages with links
  • Allowing someone to remotely access your computer

How do I prevent it?

The best way to protect yourself against a malware infection is to install appropriate software on your computer.

Anti-malware solutions differ in effectiveness and the range of malware types they cover. Some may only scan for existing viruses; others will detect malware hidden in downloaded files or sitting on the website you’ve just opened. Some packages will block downloads, or clean software as it’s downloaded.

At a minimum, all anti-malware software solutions should be able to scan for viruses and alert you to any potential malware.  Some products may also include alerts when you visit a suspicious or dangerous website, and firewall protection.

To select the right solution for your needs, we recommend you do some research on the various products on the market. Some products are available for free, while others cost money – either a one-time cost, or an ongoing subscription. Paid products may provide more tools than free ones, depending on your requirements.

Anti-virus software

The following software listings provide overviews of anti-virus software for both Mac and Windows. Note that most of the packages listed have paid subscriptions, but some may have free trials or limited-service versions.

Generally, if the same software names keep occurring in lists and articles, they are well-known and relatively trustworthy.

Note that many of these listings will differentiate between malware, spyware, and virus software. Some packages cover all three terms; some will do just one or two.

Virus scanners

On-demand virus scanners only check for viruses when you run them. They will not proactively prevent you from malware, but may be useful to do a quick check of your computer before you download and install a preventative package.

Anti-virus software

These may be a little more specific than anti-malware software in general, particularly the free packages.

Windows 10 – built-in malware scanner

Windows 10 has a built-in malware scanner as part of its Windows Security suite; Microsoft Defender Antivirus.  Defender will search for any files or programs on your computer that can cause harm to it, across email, apps, the cloud and the internet.

Be careful however, as Defender is only updated when Windows 10 is updated. Like any other virus program, if this is not done regularly then it may be unaware of, and unable to detect, newer forms of malware.

We recommend you turn on automatic updates for Windows to keep yourself protected.

Additional Protection Tips

  • Ensure anti-malware programs remain updated.
  • Protect your Wi-Fi with a complex password that has numbers, letters and characters (such as ! @ $ % etc.)
  • Avoid using free public Wi-Fi if possible – these can infect your device.
  • Back up your entire computer, as well as important files – both to a local hard drive and a cloud-based service, if possible. This particularly helps with ransomware, as you can simply re-install an earlier, clean version of your files.
  • Be cautious in opening emails from people or companies you don’t know. (Even un-expected emails from friends, as they may have been compromised)
  • Don’t allow anyone to remotely access your computer.

How do I remove malware from my computer?

Sometimes, despite taking precautions, infections do occur.  Some of the signs include:

  • Web browser freezing or becoming unresponsive.
  • You get redirected to web pages other than the ones you are trying to visit.
  • You see a lot of pop-up messages.
  • Your computer runs slower than usual.
  • New icons appear on your desktop that you don’t recognise..
  • Your computer crashes completely (you may see the Windows error screen or a blank screen on an Apple Mac).

Blue Screen of Death

If this happens, try the following steps:

  • Remove external drives and devices from your computer. Restart in Safe Mode (see “Tech Tips” for help).
  • Run a scan on your anti-virus software and follow instructions to remove any malware.
  • Restart your computer (see “Tech Tips” for help).
  • Update your operating system, browser and applications as necessary (if not current).
  • Reset all of your passwords.

The following is a list of software that may help in removing an existing malware attack/infection. Some may not help in preventing an infection in the first place, however, and you may need to install separate software for that.

The following list is specifically for removing spyware – software designed to “spy” on what you do on your computer.

Additional Information and Resources

The Australian Cyber Security Centre provides a wide range of resources and further information, specifically tailored to individuals, families, and business users.

The ACCC has information about ransomware and malware in its “threats and extortion” section: What is malware and ransomware?