Information
This rule prevents Outlook from creating child processes, while still allowing legitimate Outlook functions.
Rule ID and name:
- 26190899-1602-49e8-8b27-eb1d0a1ce869 (Block Office communication application from creating child processes)
The recommended state for this setting is: 26190899-1602-49e8-8b27-eb1d0a1ce869:2 (Audit). Configuring this setting to 26190899-1602-49e8-8b27-eb1d0a1ce869:1 (Block) also conforms to the benchmark.
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
This ASR rule protects against social engineering attacks and prevents exploiting code from abusing vulnerabilities in Outlook. It also protects against Outlook rules and forms exploits that attackers can use when a user's credentials are compromised.
Solution
To establish the recommended configuration via GP, set the following UI path to 26190899-1602-49e8-8b27-eb1d0a1ce869 with a value of 2 or 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:
This rule will block DLP policy tips and ToolTips in Outlook and applies to Outlook and Outlook.com only.