If your Mac has started acting strangely, opening unwanted pop-ups, running hot, or redirecting your browser, it is reasonable to wonder whether you are dealing with malware. Many people assume Macs cannot get infected, but adware, browser hijackers, fake updates, malicious extensions, and unwanted login items can all affect macOS.
This guide explains how to check your Mac for malware using built-in tools, manual inspection steps, and safe cleanup actions. You will also learn what signs to look for, when to use a malware scanner, and what to do if the infection keeps coming back.
Key Takeaways
- Macs have built-in protections, but they do not catch every type of malware or unwanted software.
- You can often spot problems by checking Activity Monitor, Login Items, browser extensions, Applications, and privacy permissions.
- Safe cleanup usually starts with disconnecting from the internet, removing suspicious apps, deleting related files, and updating macOS.
- If manual steps do not solve the issue, a reputable Mac malware scanner can help find hidden components.
- Persistent infections may require Safe Mode troubleshooting, restoring from a clean backup, or reinstalling macOS.
Signs Your Mac May Be Infected
Unusual performance and system behavior
Malware does not always announce itself clearly. Sometimes the first signs are indirect, such as your Mac slowing down, fans running constantly, battery draining faster than usual, or apps crashing for no obvious reason.
These symptoms can also come from normal software problems, so they are not proof by themselves. Still, if they appear alongside browser issues or unknown apps, they are worth investigating.
Browser redirects, pop-ups, and fake alerts
One of the most common Mac problems is adware rather than a classic virus. You may see search redirects, a changed homepage, repeated pop-ups claiming your Mac is infected, or prompts to install a “cleaner” or “security update.”
If this is happening, the cause is often a malicious extension, profile, or bundled app. That means your browser and system settings both need to be checked.
Unknown apps, extensions, or login items
If you notice software you did not install, that is a major warning sign. The same applies to unfamiliar browser extensions, menu bar utilities, and login items that launch automatically when you sign in.
Malware on Mac often tries to persist by reopening after restart. That is why startup-related checks are an important part of any cleanup.
Built-In macOS Tools to Check for Malware
Check Activity Monitor for suspicious processes
Open Activity Monitor and review processes that are using unusually high CPU, memory, or energy. Look for names you do not recognize, especially if they match the timing of the problem.
Be careful here. Many legitimate macOS background processes have unfamiliar names, so do not delete system items just because they look technical.
Review Login Items and background permissions
Go to System Settings and check Login Items. Look for apps or background items you do not recognize or no longer need.
This step matters because adware and unwanted software often adds itself here to relaunch after every reboot. Digital Trends also highlights Login Items and Full Disk Access as useful places to inspect when checking a Mac for malware: how to check your Mac for viruses and malware.
Inspect Applications, Profiles, and extensions
Open your Applications folder and sort through recently added apps. Remove anything suspicious, especially software you do not remember installing or apps that arrived with another download.
Then check for configuration profiles if your Mac is not managed by work or school. Unexpected profiles can lock in browser settings, search engines, or security permissions.
Also inspect browser extensions in Safari, Chrome, or Firefox. A malicious extension can cause redirects, inject ads, and monitor browsing activity.
Use XProtect, Gatekeeper, and system updates
macOS includes built-in protections such as Gatekeeper and XProtect. These help block known malicious software and reduce the risk of running unsafe apps, but they are not a complete cleanup solution once something unwanted is already on the system.
Make sure macOS is fully updated. Security updates can remove known threats and close vulnerabilities that malware may abuse.
Quick Tip: If you are unsure whether a process or app is malicious, first look for signs of persistence, such as a login item, browser extension, launch agent, or repeated reappearance after deletion.
Manual Steps to Check Your Mac for Malware
Disconnect from the internet and restart
If you believe your Mac may be compromised, disconnect from Wi-Fi or unplug Ethernet before you start. This can stop some malware from communicating with remote servers or downloading more components.
Then restart your Mac. If the problem appears immediately after login, that often points to a startup item, extension, or background process.
Boot into Safe Mode
Safe Mode loads only essential components and can make malware troubleshooting easier. It may also stop certain unwanted apps from launching automatically.
If you need a general reference for Safe Mode and malware removal workflow, Kaspersky provides a practical overview here: how to check for malware on Mac.
Remove suspicious apps and related files
Drag suspicious apps to the Trash, but do not stop there. Many unwanted programs leave behind support files, launch agents, caches, and helpers that can reinstall or relaunch the app.
Check common folders such as Library/Application Support, Library/LaunchAgents, and Library/LaunchDaemons for related items. Only remove files you can confidently connect to the suspicious app.
Reset browser settings carefully
If your main symptoms are browser-based, reset the affected browser. Remove suspicious extensions, change your default search engine back to your preferred option, and review homepage, notification, and website permission settings.
You should also clear website data and cookies if redirects or fake security alerts continue.
When to Use a Malware Scanner
Why a scanner can help
Manual checks are useful, but they can miss hidden files, scripts, or persistence mechanisms. A reputable Mac malware scanner can detect known threats faster and may quarantine items safely.
This is especially helpful if you suspect adware bundles, trojans hidden in fake installers, or unwanted files spread across several folders.
What to look for in a Mac security tool
Choose a well-known tool with real-time protection optional, clear detection results, and straightforward quarantine or removal steps. Avoid apps that use scare tactics, constant fake alerts, or aggressive upsells.
Setapp has a useful overview of the difference between manual removal and third-party scanning: how to scan for viruses on Mac.
| Approach | Best for | Main limitation |
|---|---|---|
| Built-in macOS tools | Initial checks and basic cleanup | May not reveal all hidden malware components |
| Manual inspection | Removing obvious apps, extensions, and startup items | Requires care and some technical confidence |
| Reputable malware scanner | Finding known threats and leftover files | Quality varies, and some tools are overly aggressive |
What to Do if You Find Malware on Your Mac
Change important passwords from a clean device
If you suspect credential theft, do not wait. Change passwords for email, banking, cloud storage, and your Apple account from a different trusted device if possible.
Also review whether two-factor authentication is enabled on your important accounts. That adds protection even if a password was exposed.
Check permissions and account security
Review Full Disk Access, Accessibility, Screen Recording, and other sensitive permissions in System Settings. Remove access for apps you do not trust or no longer use.
Then check your browser for saved passwords, autofill entries, and notification permissions. Malicious sites sometimes abuse browser notifications to keep sending fake alerts after the original infection is gone.
Update, rescan, and monitor
After removing suspicious items, update macOS and your browsers fully. Then run another scan or repeat your manual checks to confirm the infection is not returning.
Watch the Mac for a few days. If pop-ups, redirects, or unknown processes come back, there may still be a hidden persistence file or compromised backup.
If the Infection Keeps Coming Back
Restore from a known-clean backup
If you use Time Machine or another backup system, restoring can help, but only if the backup was created before the infection. Restoring from an already compromised backup can bring the problem right back.
When in doubt, inspect the backup date carefully and avoid restoring suspicious apps or settings.
Erase and reinstall macOS
For persistent infections, a clean reinstall is often the most reliable fix. Back up personal files carefully, erase the Mac, reinstall macOS, and reinstall apps only from trusted sources.
Do not immediately restore everything wholesale. Bring back documents and photos first, then add apps one by one.
Quick Tip: After a reinstall, avoid using old browser profiles, extension sync, or app bundles until you are sure they were not part of the original problem.
How to Reduce the Risk of Future Mac Malware
Download software carefully
Most Mac infections start with a download the user allowed. Stick to trusted sources, read installer screens closely, and avoid “free” utilities that promise to speed up, clean, or secure your Mac without a clear reputation.
Be especially cautious with fake Flash updates, codec prompts, cracked software, and search helper tools.
Keep your system and browser tidy
Regularly review installed apps, browser extensions, and login items. If you do not use something, remove it.
Good digital hygiene makes it easier to notice suspicious changes quickly and reduces the number of places malware can hide.
Use layered protection
For many users, the best approach is layered protection: macOS security features, careful download habits, browser awareness, and a reputable scanner when needed. No single tool catches everything, but a layered approach greatly improves your chances of spotting problems early.
Frequently Asked Questions
Can Macs really get malware?
Yes. Macs have strong built-in security, but they can still be affected by adware, trojans, malicious browser extensions, fake installers, and other unwanted software.
How do I know if a process in Activity Monitor is malware?
A process is suspicious if it uses unusual resources, appears alongside other symptoms, has no clear publisher, or keeps returning after you close it. However, many legitimate macOS processes look unfamiliar, so confirm before removing anything.
Is Safe Mode enough to remove malware from a Mac?
Not always. Safe Mode can make troubleshooting easier by limiting startup items, but you may still need to remove apps, extensions, launch agents, and related files manually or use a reputable malware scanner.
Should I reinstall macOS if I suspect an infection?
Only if the issue is persistent, severe, or keeps returning after normal cleanup. A clean reinstall is often the most reliable final step, especially if you cannot identify all infected components.