Windows Defender AV must monitor for incoming and outgoing files.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-75221	WNDF-AV-000018	SV-89901r2_rule		Medium

Description
This policy setting allows you to configure monitoring for incoming and outgoing files without having to turn off monitoring entirely. It is recommended for use on servers where there is a lot of incoming and outgoing file activity but for performance reasons need to have scanning disabled for a particular scan direction. The appropriate configuration should be evaluated based on the server role. Note that this configuration is only honored for NTFS volumes. For any other file system type full monitoring of file and program activity will be present on those volumes. The options for this setting are mutually exclusive: 0 = Scan incoming and outgoing files (default) 1 = Scan incoming files only 2 = Scan outgoing files only Any other value or if the value does not exist resolves to the default (0). If you enable this setting the specified type of monitoring will be enabled. If you disable or do not configure this setting monitoring for incoming and outgoing files will be enabled.

Description

This policy setting allows you to configure monitoring for incoming and outgoing files without having to turn off monitoring entirely. It is recommended for use on servers where there is a lot of incoming and outgoing file activity but for performance reasons need to have scanning disabled for a particular scan direction. The appropriate configuration should be evaluated based on the server role. Note that this configuration is only honored for NTFS volumes. For any other file system type full monitoring of file and program activity will be present on those volumes. The options for this setting are mutually exclusive: 0 = Scan incoming and outgoing files (default) 1 = Scan incoming files only 2 = Scan outgoing files only Any other value or if the value does not exist resolves to the default (0). If you enable this setting the specified type of monitoring will be enabled. If you disable or do not configure this setting monitoring for incoming and outgoing files will be enabled.

STIG	Date
MS Windows Defender Antivirus Security Technical Implementation Guide	2019-03-12

Details

Check Text ( C-75013r3_chk )
Verify the policy value for Computer Configuration -> Administrative Templates -> Windows Components -> Windows Defender Antivirus -> Real-time Protection -> "Configure monitoring for incoming and outgoing file and program activity" is set to "Disabled" or "Not Configured". Procedure: Use the Windows Registry Editor to navigate to the following key: HKLM\Software\Policies\Microsoft\Windows Defender\Real-Time Protection Criteria: If the value "RealtimeScanDirection" is REG_DWORD = 0, this is not a finding. If the value does not exist, this is not a finding. If the value is 1 or 2, this is a finding.

Check Text ( C-75013r3_chk )

Verify the policy value for Computer Configuration -> Administrative Templates -> Windows Components -> Windows Defender Antivirus -> Real-time Protection -> "Configure monitoring for incoming and outgoing file and program activity" is set to "Disabled" or "Not Configured".

Procedure: Use the Windows Registry Editor to navigate to the following key:
HKLM\Software\Policies\Microsoft\Windows Defender\Real-Time Protection

Criteria: If the value "RealtimeScanDirection" is REG_DWORD = 0, this is not a finding.

If the value does not exist, this is not a finding.

If the value is 1 or 2, this is a finding.

Fix Text (F-81831r2_fix)
Set the policy value for Computer Configuration -> Administrative Templates -> Windows Components -> Windows Defender Antivirus -> Real-time Protection -> "Configure monitoring for incoming and outgoing file and program activity" to "Disabled" or "Not Configured".