What is Malware & How To Prevent it?
A torch app that quietly copies your banking login. A pop-up claiming to be Microsoft that locks your screen until you ring a “technician”. A text about an unpaid toll with a link you almost tapped. Malware comes in many disguises, and Australians report it in huge numbers every year. This guide explains what it is, how it gets in, and what actually keeps it out.
What is malware?
Malware is short for malicious software: any program built to work against the person whose device it is running on. Some of it steals, some of it spies, some of it holds your files hostage, and some simply uses your computer to attack someone else. It reaches phones and tablets as readily as laptops.
The main types of malware
Ransomware encrypts your files and demands payment for the key. It is the most damaging kind for households and small businesses, because paying does not guarantee you get anything back.
Trojans pretend to be something useful, such as a free game, a cracked app or an invoice attachment. Once you run one, it opens a door for whoever sent it.
Spyware and keyloggers watch what you do. Keyloggers record every key you press, which is how passwords and card numbers are captured. “Stalkerware” installed by someone with access to your phone falls into this group.
Viruses attach themselves to files and spread when those files are shared. Worms go one step further and spread across networks on their own, with no help from you. Some of the most destructive outbreaks on record have been worms.
Rootkits bury themselves deep in the operating system to hide other malware and keep control of the device.
Adware floods you with advertising. It is the least dangerous on this list, though it often arrives bundled with something worse.
How malware gets in
- Phishing emails and texts with a link or attachment. This is the big one.
- Fake apps and downloads, especially cracked software and apps from outside the official stores.
- Out-of-date software with security holes that have already been fixed in newer versions.
- Malicious ads and compromised websites.
- USB drives of unknown origin.
Can a VPN stop malware?
Mostly no, and it is worth being clear about that. A VPN encrypts your connection and hides your IP address. It does not scan files, and it will not stop you opening a dodgy attachment.
Where a VPN helps is around the edges. On public Wi-Fi it stops someone on the same network tampering with what you receive. Several VPNs also bundle a blocker for known malicious sites, ads and trackers; you can see which in the features table of each of our VPN reviews. Treat that as a useful extra, not a replacement for security software.
How to protect yourself
- Keep everything updated. Turn on automatic updates for your operating system, browser and apps. Most infections use holes that already have a fix.
- Use security software. The protection built into Windows and macOS is good. Keep it switched on.
- Back up your files. An external drive or cloud backup turns ransomware from a disaster into an inconvenience. Test that you can restore from it.
- Slow down on links. Check the sender, hover to see where a link really goes, and go to the site directly instead of tapping through.
- Install from official stores and read what permissions an app asks for.
- Use a password manager and two-factor authentication, so one stolen password does not unlock everything.
If you think you are infected
- Disconnect the device from the internet.
- Run a full scan with your security software.
- From a different, clean device, change the passwords for your email and banking first.
- Call your bank straight away if you entered card or account details anywhere suspicious.
- Report it. In Australia you can report cybercrime through ReportCyber at cyber.gov.au and scams to Scamwatch. If your identity documents may be exposed, IDCARE offers free support.
FAQ
Can iPhones and Macs get malware?
Yes. It is less common than on Windows and Android, but both are targeted, particularly through phishing and fake apps.
Is free antivirus good enough?
For most people the security built into current versions of Windows and macOS, kept up to date, is a solid baseline.
Does a VPN protect against hackers?
It protects your connection from snooping, which matters most on public Wi-Fi. It does not protect against malware you install yourself. More in do I need a VPN?