4946(S): A change has been made to Windows Firewall exception list. A rule was added.

Event 4946 illustration

Subcategory: Audit MPSSVC Rule-Level Policy Change

Event Description:

This event generates when new rule was locally added to Windows Firewall.

This event doesn't generate when new rule was added via Group Policy.

Note  For recommendations, see Security Monitoring Recommendations for this event.


Event XML:

- <Event xmlns="http://schemas.microsoft.com/win/2004/08/events/event">
- <System>
 <Provider Name="Microsoft-Windows-Security-Auditing" Guid="{54849625-5478-4994-A5BA-3E3B0328C30D}" /> 
 <EventID>4946</EventID> 
 <Version>0</Version> 
 <Level>0</Level> 
 <Task>13571</Task> 
 <Opcode>0</Opcode> 
 <Keywords>0x8020000000000000</Keywords> 
 <TimeCreated SystemTime="2015-10-03T20:05:42.078367200Z" /> 
 <EventRecordID>1050893</EventRecordID> 
 <Correlation /> 
 <Execution ProcessID="500" ThreadID="528" /> 
 <Channel>Security</Channel> 
 <Computer>DC01.contoso.local</Computer> 
 <Security /> 
 </System>
- <EventData>
 <Data Name="ProfileChanged">All</Data> 
 <Data Name="RuleId">{F2649D59-1355-4E3C-B886-CDD08B683199}</Data> 
 <Data Name="RuleName">Allow All Rule</Data> 
 </EventData>
 </Event>

Required Server Roles: None.

Minimum OS Version: Windows Server 2008, Windows Vista.

Event Versions: 0.

Field Descriptions:

Profile Changed [Type = UnicodeString]: the list of profiles to which new rule was applied. Examples:

  • All

  • Domain, Public

  • Domain, Private

  • Private, Public

  • Public

  • Domain

  • Private

Added Rule:

  • Rule ID [Type = UnicodeString]: the unique new firewall rule identifier.

    To see the unique ID of the rule, you need to navigate to “HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\SharedAccess\Parameters\FirewallPolicy\FirewallRules” registry key and you'll see the list of Windows Firewall rule IDs (Name column) with parameters:

Registry Editor FirewallRules key illustration
  • Rule Name [Type = UnicodeString]: the name of the rule that was added. You can see the name of Windows Firewall rule using Windows Firewall with Advanced Security management console (wf.msc), check “Name” column:
Windows Firewall with Advanced Security illustration

Security Monitoring Recommendations

For 4946(S): A change has been made to Windows Firewall exception list. A rule was added.

  • This event can be helpful in case you want to monitor all creations of new Firewall rules that were done locally.