Quick answers to the five questions asked most
These are the five questions that bring most people to a page like this one. Each has a fuller treatment on a topic page, but if you only have a minute, the short versions are here.
Is my computer infected?
You cannot tell from symptoms alone, and no page can tell you from the other side of a browser. Slowness, noisy fans and a browser that opens on an unfamiliar page all have mundane explanations that are more likely than malicious software. Narrow the symptom to a cause rather than guess.
Is the security already built into my operating system enough?
For a lot of households, yes. Windows and macOS include protection that is enabled by default and updated with the system. A paid product is a reasonable purchase when you want extra features, cover for several devices on one licence, or a single place to manage a family's machines. It is not a requirement, and no law in Australia obliges you to buy one.
I entered my details on a page I now distrust. What now?
Change the password for that account first, from a different device if you have one, then any other account using the same password. Turn on multi-factor authentication where the service offers it. If banking details were involved, telephone your bank on the number printed on your card rather than any number in the message.
Why do I keep getting messages about a parcel I never ordered?
Because that pattern costs the sender almost nothing and occasionally works. Messages about a delivery problem, a small fee or a toll notice are among the most reported categories to Scamwatch. Nothing on your device needs fixing; the message simply arrived at a number a sender had.
Does a phone need the same thing a laptop needs?
No, and the difference matters. Mobile operating systems keep apps separated, and on iOS one app may not scan another, so a mobile security app cannot work the way a desktop scanner does. Updates and the official store do most of the useful work on a phone.
Every question on this site, grouped by topic
Each topic page gathers related questions in the same shape: short answer, likely causes, what to try at no cost, when to ask an official source, and only then where a paid product may or may not help.
My computer has slowed down
- My computer became slow this week. Is that a virus?
- Why is the fan loud even when I am not doing anything?
- Why does it take so long to start up?
- The whole computer is fine but the browser crawls. Why?
- How much free disk space do I actually need?
- Should I install a cleaner or optimiser to speed it up?
- At what point is the machine simply too old?
Phones and tablets
- Do I need a security app on my phone?
- Why is the answer different for iPhone and Android?
- An app asked for permissions that seem excessive. What should I do?
- My battery drains quickly. Is something running that should not be?
- My phone no longer receives updates. How much does that matter?
- What should I set up on a child's device?
Messages, calls and payment requests
- How can I tell whether a message is genuine?
- Why do I get so many parcel and toll messages?
- Someone phoned saying my computer has a problem. Is that ever real?
- I let someone connect to my computer remotely. What now?
- Where do I report it, and is reporting worth the time?
- Can I stop the messages arriving at all?
Symptom and likely cause
This table is a starting point, not a diagnosis. It lists the explanations responsible most often, so you check the ordinary things before the alarming ones.
| What you notice | Causes worth checking first | Where it is covered |
|---|---|---|
| Everything is slower than it was a month ago | Disk close to full, an update installing, a browser holding many tabs or extensions, an ageing drive | Slow computer |
| Fans run constantly | Dust blocking vents, background indexing or backup, a browser tab with video or animation | Slow computer |
| Pop-ups appear while browsing one site | Advertising on that site, not the computer; an extension inserting ads | Slow computer |
| The browser opens on an unfamiliar page | A changed homepage setting, usually from bundled software installed alongside something else | Slow computer |
| Messages about parcels, tolls or refunds | Bulk messaging to many numbers; nothing on your device caused it | Scam messages |
| Phone battery drains faster than before | Battery age, a recent system update, an app refreshing in the background | Phones and tablets |
| A warning page says your device is infected | An advertisement imitating a system message; closing the tab is the whole response | Scam messages |
Free steps worth trying before you spend anything
Most of what improves a home computer's behaviour costs nothing and takes under an hour. Work through these in order.
- Install the operating system updates that are waiting, then restart. A restart alone resolves a surprising share of complaints, because it completes installations that were paused.
- Check free disk space. A drive with very little headroom slows the whole system, because the operating system needs room to work in.
- Open the browser's extension list and remove anything you do not recognise or no longer use. Extensions have broad access to the pages you visit and are a frequent cause of odd browsing behaviour.
- Look at which programs start automatically with the computer and switch off the ones you do not need from the first minute.
- Confirm the protection built into your system is switched on. On Windows this is in the security settings; on macOS the equivalent protections are part of the system and are not presented as a separate product.
- Set up a backup, whether to an external drive or a cloud service you already pay for. Backups are the one measure that helps regardless of what goes wrong.
When the problem is not the software
A fair number of problems that arrive described as security problems are nothing of the sort. Hardware ages. A mechanical hard drive that has spun for seven years is slower than it was, and no amount of scanning changes that. Laptop vents fill with dust, the machine runs hot, and the processor deliberately slows itself to stay within its temperature limit. A battery that has been through several hundred charge cycles holds less than it did when new.
Connections are another frequent culprit. A video call that stutters usually points at the network rather than the device. Before replacing anything, try the same task on a second device on the same connection: if both behave the same way, the device is not the variable.
There is also the ordinary accumulation of use. A browser carrying twelve extensions, a cloud drive syncing a large folder and a game launcher updating in the background will together make a healthy computer feel tired.
Where a paid product fits, and where it does not
Paid security software answers a narrower question than people often expect. It is designed primarily to stop harmful files from running, and to manage that protection across the devices a licence covers. Norton AntiVirus Plus is a paid antivirus product of that kind; we do not reproduce its feature list, pricing or terms here, because those change and the vendor's own site is the accurate source.
It is equally worth being clear about what a product of this category does not address. It does not stop you from typing a password into a convincing imitation of a bank's sign-in page. It does not recover money already transferred. It does not make an eight-year-old laptop faster, repair a failing drive, or stop scam text messages from arriving on your phone. If the problem you have is one of those, buying software is simply the wrong tool, and the relevant topic page explains what the right one is.
The link below is a paid affiliate link. If you sign up after following it, the publisher of this site earns a commission at no additional cost to you.
Visit the Norton AntiVirus Plus website if you want to read the vendor's own description of what the product covers and what it costs in Australian dollars.
Reporting a scam or harmful content in Australia
Reporting takes a few minutes and goes to organisations whose job it is to act on patterns rather than individual messages. Each link goes to the organisation's own site, where its role is described in its own words.
- Scamwatch — run by the National Anti-Scam Centre at the ACCC, it collects reports about scams and publishes warnings about current ones.
- The Australian Cyber Security Centre — part of the Australian Signals Directorate, it publishes security advice for individuals and businesses, and takes cybercrime reports through ReportCyber.
- The eSafety Commissioner — the regulator for online safety, which handles reports about seriously harmful online content and about image-based abuse, cyberbullying and adult cyber abuse.
- The ACCC — the national competition and consumer regulator, whose remit includes misleading conduct by businesses selling to Australians.
- The OAIC — the national privacy regulator, which oversees the handling of personal information and the Notifiable Data Breaches scheme.
- The Australian Classification Board — the source for classification decisions on games and other content, if a question of suitability comes up on a household device.
How these answers are written and checked
Questions are chosen from the wording people use when they describe a problem, and an answer is added only when there is something useful to say that does not depend on seeing the device. Each one is checked against the published guidance of the Australian bodies listed above and against vendor documentation, and the date of the most recent review appears in every footer. The about page sets out the method in full, including the commercial relationship behind the links described in our disclosure.
Words you will meet in these answers
- Malware
- A general term for software written to do something the person running it would not agree to. Viruses are one old category within it.
- Phishing
- A message designed to get you to hand over credentials or payment details by imitating an organisation you already deal with.
- Multi-factor authentication
- A second check beyond a password, usually a code from an app or a physical key, so that a stolen password alone is not enough.
- Extension
- An add-on installed into a browser. Extensions can read and change the pages you visit, which is why an unused one is worth removing.
- Licence
- The agreement that lets you use a paid product, usually for a set number of devices and a set period, renewing until cancelled.
A short FAQ
No. Current versions of Windows and macOS ship with security protection that is turned on by default, and for a cautious user with an updated system that is often enough. Paid products exist to add further features, to cover several devices under one licence, or to give a single place to manage protection for a household. Nobody is under a legal obligation in Australia to buy one.
Usually not. A full disk, a browser carrying many extensions, an update installing in the background, an ageing mechanical drive and an overheating laptop all slow a machine down, and all are far more common than malicious software. Work through the ordinary causes before assuming the worst.
Scamwatch, run by the National Anti-Scam Centre, takes reports about scams at scamwatch.gov.au. If money or account access has been lost, the Australian Signals Directorate's Australian Cyber Security Centre takes reports through ReportCyber at cyber.gov.au. Contact your bank directly as well.
Sometimes, but not reliably. Security software is designed mainly to stop harmful files before they run. Once something is established on a system, removal can be incomplete, and a clean reinstall of the operating system is the more dependable path. If the device holds work data, ask your employer's IT contact before doing anything.
Phones work differently from desktop computers. Apps are confined from one another, and on iOS third-party scanning of other apps is not permitted at all, so an iPhone app cannot do what a desktop scanner does. Keeping the operating system updated and installing only from the official store addresses most of the real risk on mobile devices.