Microsoft Defender Antivirus in Windows Overview - Microsoft Defender for Endpoint (original) (raw)

Microsoft Defender Antivirus is available in Windows 10 and Windows 11, and in versions of Windows Server.

Microsoft Defender Antivirus is a major component of your next-generation protection in Microsoft Defender for Endpoint. This protection brings together machine learning, big-data analysis, in-depth threat resistance research, and the Microsoft cloud infrastructure to protect devices (or endpoints) in your organization. Microsoft Defender Antivirus is built into Windows, and it works with Microsoft Defender for Endpoint to provide protection on your device and in the cloud.

Prerequisites

Supported operating systems

Microsoft Defender Antivirus capabilities

Microsoft Defender Antivirus provides anomaly detection, a layer of protection for malware that doesn't fit any predefined pattern. Anomaly detection monitors for process creation events or files that are downloaded from the internet. Through machine learning and cloud-delivered protection, Microsoft Defender Antivirus can stay one step ahead of attackers. Anomaly detection is on by default and can help block attacks such as 3CX Security Alert for Electron Windows App. Microsoft Defender Antivirus started blocking this malware four days before the attack was registered in VirusTotal.

Modern malware requires modern solutions. In 2015, Microsoft Defender Antivirus moved away from using a static signature-based engine to a model that uses predictive technologies--such as machine learning, applied science, and artificial intelligence--as this switch is what's necessary to keep you and your organizations safe from the complexity of today's ever-evolving malware landscape.

Microsoft Defender Antivirus can block almost all malware at first sight, in milliseconds.

We designed our antivirus solution to work in both online and offline scenarios. For offline scenarios, the latest dynamic intelligence from the Intelligence Security Graph is provisioned to the endpoint regularly throughout the day. When connected to the cloud, real-time intelligence gets fed from the Intelligent Security Graph.

Microsoft Defender Antivirus can also stop threats based on their behaviors and process trees even when the threat has started execution. A common example of these kinds of attacks is fileless malware. Microsoft's Next-generation protection features work together to identify and block malware based on abnormal behavior. To learn more, see Behavioral blocking and containment.

Compatibility with other antivirus products

If you're using a non-Microsoft antivirus/anti-malware product on your device, you might be able to run Microsoft Defender Antivirus in passive mode alongside the non-Microsoft antivirus solution. It depends on the operating system used and whether your device is onboarded to Defender for Endpoint. To learn more, see Microsoft Defender Antivirus compatibility.

Microsoft Defender Antivirus processes and services

The following table summarizes Microsoft Defender Antivirus processes and services. You can view them in Task Manager in Windows.

Process or service Where to view its status
Microsoft Defender Antivirus Core service (MdCoreSvc) Processes tab: Antimalware Core ServiceDetails tab: MpDefenderCoreService.exeServices tab: Microsoft Defender Core Service
Microsoft Defender Antivirus service (WinDefend) Processes tab: Antimalware Service ExecutableDetails tab: MsMpEng.exeServices tab: Microsoft Defender Antivirus
Microsoft Defender Antivirus Network Realtime Inspection service (WdNisSvc) Processes tab: Microsoft Network Realtime Inspection ServiceDetails tab: NisSrv.exeServices tab: Microsoft Defender Antivirus Network Inspection Service
Microsoft Defender Antivirus command-line utility Processes tab: N/ADetails tab: MpCmdRun.exeServices tab: N/A
Microsoft Security Client Policy Configuration Tool Processes tab: N/ADetails tab: ConfigSecurityPolicy.exeServices tab: N/A

To learn more about the Microsoft Defender Core service, visit Microsoft Defender Core service overview.

For Microsoft Endpoint Data Loss Prevention (Endpoint DLP), the following table summarizes processes and services. You can view them in Task Manager in Windows.

Process or service Where to view its status
Microsoft Endpoint DLP service (MDDlpSvc) Processes tab: MpDlpService.exeDetails tab: MpDlpService.exeServices tab: Microsoft Data Loss Prevention Service
Microsoft Endpoint DLP command-line utility Processes tab: N/ADetails tab: MpDlpCmd.exeServices tab: N/A

Comparing active mode, passive mode, and disabled mode

The following table describes what to expect when Microsoft Defender Antivirus is in active mode, passive mode, or disabled.

Mode What happens
Active mode In active mode, Microsoft Defender Antivirus is used as the primary antivirus app on the device. Files are scanned, threats are remediated, and detected threats are listed in your organization's security reports and in your Windows Security app.
Passive mode In passive mode, Microsoft Defender Antivirus isn't used as the primary antivirus app on the device. Files are scanned, and detected threats are reported, but threats aren't remediated by Microsoft Defender Antivirus. IMPORTANT: Microsoft Defender Antivirus can run in passive mode only on endpoints that are onboarded to Microsoft Defender for Endpoint. See Requirements for Microsoft Defender Antivirus to run in passive mode.
Disabled or uninstalled When disabled or uninstalled, Microsoft Defender Antivirus isn't used. Files aren't scanned, and threats aren't remediated. In general, we don't recommend disabling or uninstalling Microsoft Defender Antivirus.

To learn more, see Microsoft Defender Antivirus compatibility.

Check the state of Microsoft Defender Antivirus on your device

You can use one of several methods, such as the Windows Security app or Windows PowerShell, to check the state of Microsoft Defender Antivirus on your device.

Important

Beginning with platform version 4.18.2208.0 and later: If a server has been onboarded to Microsoft Defender for Endpoint, the "Turn off Windows Defender" group policy setting no longer completely disables Windows Defender Antivirus on Windows Server 2012 R2 and later. Instead, it places it into passive mode. In addition, the tamper protection feature allows a switch to active mode but not to passive mode.

Understand the modified logic for ForceDefenderPassiveMode when tamper protection is enabled: Once Microsoft Defender Antivirus is toggled to active mode, tamper protection prevents it from going back into passive mode even when ForceDefenderPassiveMode is set to 1.

Use the Windows Security app to check the status of Microsoft Defender Antivirus

  1. On your Windows device, select the Start menu, and begin typing Security. Then open the Windows Security app in the results.
  2. Select Virus & threat protection.
  3. Under Who's protecting me?, choose Manage Providers.

You'll see the name of your antivirus/anti-malware solution on the security providers page.

Use PowerShell to check the status of Microsoft Defender Antivirus

  1. Select the Start menu, and begin typing PowerShell. Then open Windows PowerShell in the results.
  2. Type Get-MpComputerStatus.
  3. In the list of results, look at the AMRunningMode row.
    • Normal means Microsoft Defender Antivirus is running in active mode.
    • Passive mode means Microsoft Defender Antivirus running, but isn't the primary antivirus/anti-malware product on your device. Passive mode is only available for devices that are onboarded to Microsoft Defender for Endpoint and that meet certain requirements. To learn more, see Requirements for Microsoft Defender Antivirus to run in passive mode.
    • EDR Block Mode means Microsoft Defender Antivirus is running and Endpoint detection and response (EDR) in block mode, a capability in Microsoft Defender for Endpoint, is enabled. Check the ForceDefenderPassiveMode registry key. If its value is 0, it's running in normal mode; otherwise, it's running in passive mode.
    • SxS Passive Mode means Microsoft Defender Antivirus is running alongside another antivirus/anti-malware product, and limited periodic scanning is used.

Tip

To learn more about the Get-MpComputerStatus PowerShell cmdlet, see the reference article Get-MpComputerStatus.

Performance tip Due to a variety of factors (examples listed below) Microsoft Defender Antivirus, like other antivirus software, can cause performance issues on endpoint devices. In some cases, you might need to tune the performance of Microsoft Defender Antivirus to alleviate those performance issues. Microsoft's Performance analyzer is a PowerShell command-line tool that helps determine which files, file paths, processes, and file extensions might be causing performance issues; some examples are:

You can use the information gathered using Performance analyzer to better assess performance issues and apply remediation actions. See: Performance analyzer for Microsoft Defender Antivirus.

Get your antivirus/anti-malware platform updates

It's important to keep Microsoft Defender Antivirus (or any antivirus/anti-malware solution) up to date. Microsoft releases regular updates to help ensure that your devices have the latest technology to protect against new malware and attack techniques. To learn more, see Manage Microsoft Defender Antivirus updates and apply baselines.

Tip

See also