Microsoft Defender Antivirus Security Technical Implementation Guide (V2 R4)

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ArchivedPublished Tue May 31 2022

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V-213426

high

After enabling this feature, PUA protection blocking takes effect on endpoint clients after the next signature update or computer restart. Signature updates take place daily under typical circumstances. PUA will be blocked and automatically quarantined.

V-213427

medium

This policy setting allows Microsoft Defender configuration to automatically take action on all detected threats. The action to be taken on a particular threat is determined by the combination of the policy-defined action user-defined action and the signature-defined action. If this policy setting is enabled, Microsoft Defender does not automatically take action on the detected threats but prompts users to choose from the actions available for each threat. If this policy setting is disabled or not configured, Microsoft Defender automatically takes action on all detected threats after a nonconfigurable delay of approximately five seconds.

V-213428

high

This policy setting turns off Microsoft Defender Antivirus. If this policy setting is enabled, Microsoft Defender Antivirus does not run and computers are not scanned for malware or other potentially unwanted software.

When the setting is disabled and a third-party antivirus solution is installed, the two applications can both simultaneously try to protect the system. The two AV solutions both attempt to quarantine the same threat and will fight for access to delete the file. Users will see conflicts and the system may lock up until the two solutions finish processing.

When the setting is not configured and a third-party antivirus solution is installed, both applications coexist on the system without conflicts. Defender Antivirus will automatically disable itself and will enable if the third-party solution stops functioning. When the setting is not configured and Defender Antivirus is the only AV solution, Defender AV will run (default state) and receive definition updates. An administrator account is needed to turn off the service. A standard user cannot disable the service.

V-213429

medium

This policy setting allows disabling of scheduled and real-time scanning for files under the paths specified or for the fully qualified resources specified. Paths should be added under the Options for this setting. Each entry must be listed as a name value pair where the name should be a string representation of a path or a fully qualified resource name. As an example, a path might be defined as: "c:\Windows" to exclude all files in this directory. A fully qualified resource name might be defined as: "C:\Windows\App.exe". The value is not used and it is recommended that this be set to 0.

Exceptions can be made to allow file/folders that are impacting enterprise applications to be excluded from being scanned. All exclusions should be documented and approved.

V-213430

medium

This policy setting allows the disabling of scheduled and real-time scanning for any file opened by any of the specified processes. The process itself will not be excluded. To exclude the process, use the Path exclusion. Processes should be added under the options for this setting. Each entry must be listed as a name value pair where the name should be a string representation of the path to the process image. Note that only executables can be excluded. For example, a process might be defined as: "c:\windows\app.exe". The value is not used and it is recommended that this be set to 0.

V-213431

medium

This setting allows an administrator to specify if Automatic Exclusions feature for Server SKUs should be turned off.

V-213432

medium

This policy setting configures a local override for the configuration to join Microsoft MAPS. This setting can only be set by Group Policy. If this setting is enabled, the local preference setting will take priority over Group Policy. If this setting is disabled or not configured, Group Policy will take priority over the local preference setting.

V-213433

medium

This feature ensures the device checks in real time with the Microsoft Active Protection Service (MAPS) before allowing certain content to be run or accessed. If this feature is disabled, the check will not occur, which will lower the protection state of the device.

Enabled - The Block at First Sight setting is turned on.
Disabled - The Block at First Sight setting is turned off.

This feature requires these Group Policy settings to be set as follows:
MAPS >> The "Join Microsoft MAPS" must be enabled or the "Block at First Sight" feature will not function.
MAPS >> The "Send file samples when further analysis is required" should be set to 1 (Send safe samples) or 3 (Send all samples). Setting to 0 (Always Prompt) will lower the protection state of the device. Setting to 2 (Never send) means the "Block at First Sight" feature will not function.
Real-time Protection >> The "Scan all downloaded files and attachments" policy must be enabled or the "Block at First Sight" feature will not function.
Real-time Protection >> Do not enable the "Turn off real-time protection" policy or the "Block at First Sight" feature will not function.

V-213434

medium

This policy setting allows joining Microsoft MAPS. Microsoft MAPS is the online community that helps in choosing how to respond to potential threats. The community also helps stop the spread of new malicious software infections. You can choose to send basic or additional information about detected software. Additional information helps Microsoft create new definitions and protect your computer. This information can include things like location of detected items on your computer if harmful software was removed. The information will be automatically collected and sent. In some instances personal information might unintentionally be sent to Microsoft. However Microsoft will not use this information to identify you or contact you.

Possible options are:
(0x0) Disabled (default)
(0x1) Basic membership
(0x2) Advanced membership

Basic membership will send basic information to Microsoft about software that has been detected, including where the software came from, the actions that you apply or that are applied automatically, and whether the actions were successful. Advanced membership will send, in addition to basic information, more information to Microsoft about malicious software spyware and potentially unwanted software, including the location of the software file names, how the software operates, and how it has impacted your computer.

If this setting is enabled, you will join Microsoft MAPS with the membership specified. If this setting is disabled or do not configured, you will not join Microsoft MAPS. In Windows 10, Basic membership is no longer available, so setting the value to 1 or 2 enrolls the device into Advanced membership.

V-213435

medium

This policy setting configures behavior of samples submission when opt-in for MAPS telemetry is set. Possible options are:
(0x0) Always prompt
(0x1) Send safe samples automatically
(0x2) Never send
(0x3) Send all samples automatically

V-213436

medium

This policy setting allows the configuration of protocol recognition for network protection against exploits of known vulnerabilities. If this setting is enabled or not configured, protocol recognition will be enabled. If this setting is disabled, protocol recognition will be disabled.

V-213437

medium

This policy setting configures a local override for the configuration of monitoring for file and program activity on your computer. This setting can only be set by Group Policy. If this setting is enabled, the local preference setting will take priority over Group Policy. If this setting is disabled or not configured, Group Policy will take priority over the local preference setting.

V-213438

medium

This policy setting configures a local override for the configuration of monitoring for incoming and outgoing file activity. This setting can only be set by Group Policy. If this setting is enabled, the local preference setting will take priority over Group Policy. If this setting is disabled or not configured, Group Policy will take priority over the local preference setting.

V-213439

medium

This policy setting configures a local override for the configuration of scanning for all downloaded files and attachments. This setting can only be set by Group Policy. If this setting is enabled, the local preference setting will take priority over Group Policy. If this setting is disabled or not configured, Group Policy will take priority over the local preference setting.

V-213440

medium

This policy setting configures a local override for the configuration of behavior monitoring. This setting can only be set by Group Policy. If this setting is enabled, the local preference setting will take priority over Group Policy. If this setting is disabled or not configured, Group Policy will take priority over the local preference setting.

V-213441

medium

This policy setting configures a local override for the configuration to turn on real-time protection. This setting can only be set by Group Policy. If this setting is enabled, the local preference setting will take priority over Group Policy. If this setting is disabled or not configured, Group Policy will take priority over the local preference setting.

V-213442

medium

This policy setting allows the configuration of monitoring for incoming and outgoing files without having to turn off monitoring entirely. It is recommended for use on servers that have 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 this setting is enabled, the specified type of monitoring will be enabled. If this setting is disabled or not configured, monitoring for incoming and outgoing files will be enabled.

V-213443

medium

This policy setting allows configuration of monitoring for file and program activity. If this setting is enabled or not configured, monitoring for file and program activity will be enabled. If this setting is disabled, monitoring for file and program activity will be disabled.

V-213444

medium

This policy setting allows configuration of scanning for all downloaded files and attachments. If this setting is enabled or not configured, scanning for all downloaded files and attachments will be enabled. If this setting is disabled, scanning for all downloaded files and attachments will be disabled.

V-213445

medium

This policy setting turns off real-time protection prompts for known malware detection. Microsoft Defender Antivirus alerts when malware or potentially unwanted software attempts to install itself or to run on your computer. If this policy setting is enabled, Microsoft Defender Antivirus will not prompt users to take actions on malware detections. If this policy setting is disabled or not configured, Microsoft Defender Antivirus will prompt users to take actions on malware detections.

V-213446

medium

This policy setting allows configuration of behavior monitoring. If this setting is enabled or not configured, behavior monitoring will be enabled. If this setting is disabled, behavior monitoring will be disabled.

V-213447

medium

This policy setting allows the configuration of process scanning when real-time protection is turned on. This helps to catch malware, which could start when real-time protection is turned off. If this setting is enabled or not configured, a process scan will be initiated when real-time protection is turned on. If this setting is disabled, a process scan will not be initiated when real-time protection is turned on.

V-213448

medium

This policy setting allows the configuration of scans for malicious software and unwanted software in archive files such as .ZIP or .CAB files. If this setting is enabled or not configured, archive files will be scanned. If this setting is disabled, archive files will not be scanned.

V-213449

medium

This policy setting allows the management of whether or not to scan for malicious software and unwanted software in the contents of removable drives such as USB flash drives when running a full scan. If this setting is enabled, removable drives will be scanned during any type of scan. If this setting is disabled or not configured, removable drives will not be scanned during a full scan. Removable drives may still be scanned during quick scan and custom scan.

V-213450

medium

This policy setting allows specifying the day of the week on which to perform a scheduled scan. The scan can also be configured to run every day or to never run at all. This setting can be configured with the following ordinal number values:
(0x0) Every Day
(0x1) Sunday
(0x2) Monday
(0x3) Tuesday
(0x4) Wednesday
(0x5) Thursday
(0x6) Friday
(0x7) Saturday
(0x8) Never (default)

If this setting is enabled, a scheduled scan will run at the frequency specified. If this setting is disabled or not configured, a scheduled scan will run at a default frequency.

V-213451

medium

This policy setting allows the configuration of e-mail scanning. When e-mail scanning is enabled, the engine will parse the mailbox and mail files according to their specific format in order to analyze the mail bodies and attachments. Several e-mail formats are currently supported, for example: pst (Outlook), dbx mbx mime (Outlook Express), binhex (Mac). If this setting is enabled, e-mail scanning will be enabled. If this setting is disabled or not configured, e-mail scanning will be disabled.

V-213452

high

This policy setting allows defining the number of days that must pass before spyware definitions are considered out of date. If definitions are determined to be out of date, this state may trigger several additional actions, including falling back to an alternative update source or displaying a warning icon in the user interface. By default this value is set to 14 days.

If this setting is enabled, spyware definitions will be considered out of date after the number of days specified have passed without an update. If this setting is disabled or not configured, spyware definitions will be considered out of date after the default number of days have passed without an update.

V-213453

high

This policy setting allows defining the number of days that must pass before virus definitions are considered out of date. If definitions are determined to be out of date, this state may trigger several additional actions, including falling back to an alternative update source or displaying a warning icon in the user interface. By default, this value is set to 14 days.

If this setting is enabled, virus definitions will be considered out of date after the number of days specified have passed without an update. If this setting is disabled or not configured, virus definitions will be considered out of date after the default number of days have passed without an update.

V-213454

medium

This policy setting allows specifying the day of the week on which to check for definition updates. The check can also be configured to run every day or to never run at all. This setting can be configured with the following ordinal number values:
(0x0) Every Day (default)
(0x1) Sunday
(0x2) Monday
(0x3) Tuesday
(0x4) Wednesday
(0x5) Thursday
(0x6) Friday
(0x7) Saturday
(0x8) Never

If this setting is enabled, the check for definition updates will occur at the frequency specified. If this setting is disabled or not configured, the check for definition updates will occur at a default frequency.

V-213455

medium

This policy setting allows the customization of which automatic remediation action will be taken for each threat alert level. Threat alert levels should be added under the Options for this setting. Each entry must be listed as a name value pair. The name defines a threat alert level. The value contains the action ID for the remediation action that should be taken.

Valid threat alert levels are:
1 = Low
2 = Medium
4 = High
5 = Severe

Valid remediation action values are:
2 = Quarantine
3 = Remove
6 = Ignore

V-213456

medium

This rule blocks the following file types from being run or launched from an email seen in either Microsoft Outlook or webmail (such as Gmail.com or Outlook.com):
Executable files (such as .exe, .dll, or .scr)
Script files (such as a PowerShell .ps, VisualBasic .vbs, or JavaScript .js file)
Script archive files

V-213457

medium

Office apps, such as Word or Excel, will not be allowed to create child processes. This is a typical malware behavior, especially for macro-based attacks that attempt to use Office apps to launch or download malicious executables.

V-213458

medium

This rule targets typical behaviors used by suspicious and malicious add-ons and scripts (extensions) that create or launch executable files. This is a typical malware technique. Extensions will be blocked from being used by Office apps. Typically these extensions use the Windows Scripting Host (.wsh files) to run scripts that automate certain tasks or provide user-created add-on features.

V-213459

medium

Office apps, such as Word, Excel, or PowerPoint, will not be able to inject code into other processes. This is typically used by malware to run malicious code in an attempt to hide the activity from antivirus scanning engines.

V-213460

medium

JavaScript and VBScript scripts can be used by malware to launch other malicious apps. This rule prevents these scripts from being allowed to launch apps, thus preventing malicious use of the scripts to spread malware and infect machines.

V-213461

medium

Malware and other threats can attempt to obfuscate or hide their malicious code in some script files. This rule prevents scripts that appear to be obfuscated from running. It uses the AntiMalwareScanInterface (AMSI) to determine if a script is potentially obfuscated and then blocks such a script or blocks scripts when an attempt is made to access them.

V-213462

medium

This rule blocks potentially malicious behavior by not allowing macro code to execute routines in the Win 32 dynamic link library (DLL).

V-213463

medium

Enable Microsoft Defender Exploit Guard network protection to prevent employees from using any application to access dangerous domains that may host phishing scams, exploit-hosting sites, and other malicious content on the internet.

V-213464

medium

V-213465

medium

V-213466

medium