Information
This rule blocks email opened within the Microsoft Outlook application, or Outlook.com and other popular webmail providers from propagating the following file types:
- Executable files (such as .exe, .dll, or .scr)
- Script files (such as a PowerShell .ps1, Visual Basic .vbs, or JavaScript .js file)
Rule ID and name:
- be9ba2d9-53ea-4cdc-84e5-9b1eeee46550 (Block executable content from email client and webmail)
The recommended state for this setting is: be9ba2d9-53ea-4cdc-84e5-9b1eeee46550:1 (Block).
Note: More information on ASR rules can be found at the following link: Use Attack surface reduction rules to prevent malware infection | Microsoft Docs https://docs.microsoft.com/en-us/windows/security/threat-protection/windows-defender-exploit-guard/attack-surface-reduction-exploit-guard
Attack surface reduction helps prevent actions and apps that are typically used by exploit-seeking malware to infect machines.
Solution
To establish the recommended configuration via GP, set the following UI path to be9ba2d9-53ea-4cdc-84e5-9b1eeee46550 with a value of 1 :
Computer Configuration\Policies\Administrative Templates\Windows Components\Microsoft Defender Antivirus\Microsoft Defender Exploit Guard\Attack Surface Reduction\Configure Attack Surface Reduction rules: Set the state for each ASR rule
Note: This Group Policy path is provided by the Group Policy template WindowsDefender.admx/adml that is included with the Microsoft Windows 10 Release 1709 Administrative Templates (or newer).
Impact:
When a rule is triggered, a notification will be displayed from the Action Center.