Applies ToMicrosoft Defender on Android Microsoft Defender on Mac Microsoft Defender on Windows

Important: The National Public Data breach exposed personal information, including names, addresses, and social security numbers. Learn how to protect yourself and how Microsoft Defender is helping to prevent fraud. See: National Public Data breach: What you need to know.

Malware is malicious software and it comes in a lot of different varieties. Viruses, ransomware, spyware, and more are all types of malware. Microsoft Defender has powerful built-in features that can help protect your device against malware.

Note: Microsoft Defender currently offers anti-malware only on Windows, Mac, and Android.

When you first set-up Microsoft Defender on your device we'll run an initial scan to make sure you're starting off clean.

Using anti-malware on your device

Microsoft Defender's real-time anti-malware protection runs whenever your device is on, keeping an eye out for malicious activity.

Microsoft Defender will also run quick scans of your device on a daily basis, in case anything manages to elude the real-time protection.

If it spots something it will attempt to block it, and alert you so that you can take action if necessary.

If you're concerned and want to have Microsoft Defender run a scan right now, you can do that by going to the Device protection page from the Microsoft Defender dashboard. For more information see How to start a scan for malware in Microsoft Defender

What if Defender finds malware?

If Defender finds malware on your device it'll block it, notify you, and try to remove the malware if it can. In some instances Defender may need you to take some actions such as quarantining or removing the dangerous file or process.

For more information see What if Defender finds malware on my device?

Learn more

Protect yourself from malware and phishing

How malware can infect your PC

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