Before you start
- A Windows PC or Mac
Signs of malware
- Pop-ups and ads outside the browser.
- Browser homepage or search engine changed by itself.
- Unknown programs or extensions.
- PC much slower, fans loud when idle.
- Friends receive messages you didn’t send.
- Security software turned off without your doing.
Method 1 Windows: built-in scans
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Step 1: Run a full scan
Open Windows Security > Virus & threat protection > Scan options, choose Full scan and click Scan now. It can take an hour or more.
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Step 2: Run an offline scan
For hard-to-remove threats, choose Microsoft Defender Antivirus (offline scan). The PC restarts and scans before Windows loads.
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Step 3: Review protection history
Check Protection history for anything found and make sure it was quarantined or removed.
Method 2 Get a second opinion
Only download security tools from the official websites. Fake “antivirus” pop-ups are a common scam.
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Step 1: Malwarebytes free
Download Malwarebytes from malwarebytes.com. The free version scans and removes malware on demand (the trial of real-time protection ends after 14 days; scanning stays free).
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Step 2: ESET Online Scanner
Another free one-time scanner from a reputable vendor.
Method 3 Clean up the browser
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Step 1: Remove extensions
Remove any browser extensions you don’t recognise.
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Step 2: Reset the browser
Chrome: Settings > Reset settings. Edge: Settings > Reset settings.
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Step 3: Uninstall unknown programs
Settings > Apps > Installed apps, sort by install date and remove anything suspicious.
Method 4 Mac
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Step 1: Keep macOS updated
macOS includes XProtect, which updates automatically and blocks known malware.
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Step 2: Scan with Malwarebytes for Mac
The free version scans and removes adware and malware.
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Step 3: Check login items
System Settings > General > Login Items & Extensions: remove anything unknown.
Troubleshooting
Malware keeps coming back
Run the offline scan, check startup items and scheduled tasks, and consider resetting Windows with “Remove everything” after backing up files.
Windows Security won’t open
Malware may be blocking it. Boot into Safe Mode with Networking and run Malwarebytes.
Frequently asked questions
Is Microsoft Defender enough?
For most home users, yes, combined with updates, careful downloads and an occasional second-opinion scan.
Do Macs get viruses?
Less often, but adware and malware exist for Mac. Keep it updated and download apps from trusted sources.
Summary
Run a Full scan and an offline scan in Windows Security, get a second opinion with Malwarebytes, and clean up browser extensions and unknown programs. On Mac, keep macOS updated and scan with Malwarebytes.
