The Windows Filtering Platform has allowed a connection
A network connection (`TCP/UDP`) was permitted by Windows Filtering Platform rules (`Application Name`, `Source/Dest IP & Port`).
Event ID 5156 logs successful network connections at the kernel WFP layer (`Application Name`, `Direction`, `Source Address & Port`, `Destination Address & Port`). Essential for high-fidelity network traffic accounting and correlating process execution (`Process ID`) directly with outbound network destinations and external IP addresses during incident response.
Failure Reason / Root Cause:
Network connection permitted by WFP filter rule (`Application Name` connecting to `Destination Address`).
Raw Event XML snippet
<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>5156</EventID>
<Version>0</Version>
<Level>0</Level>
<Task>12544</Task>
<Opcode>0</Opcode>
<Keywords>0x8020000000000000</Keywords>
<TimeCreated SystemTime="2026-07-17T09:54:44.936Z" />
<EventRecordID>1048576</EventRecordID>
<Correlation />
<Execution ProcessID="612" ThreadID="1024" />
<Channel>Security</Channel>
<Computer>DC01.enterprise.internal</Computer>
<Security />
</System>
<EventData>
<Data Name="SubjectUserSid">S-1-5-18</Data>
<Data Name="SubjectUserName">SYSTEM</Data>
<Data Name="SubjectDomainName">NT AUTHORITY</Data>
<Data Name="SubjectLogonId">0x3e7</Data>
<!-- Event telemetry fields specific to The Windows Filtering Platform has allowed a connection -->
</EventData>
</Event>MITRE ATT&CK mapping
| ID | Technique | Tactic |
|---|---|---|
T1071 | Application Layer Protocol | Command and Control |
T1041 | Exfiltration Over C2 Channel | Exfiltration |
Recommended actions
- Correlate `Application Name` and `Process ID` with `4688` process creation logs when investigating outbound connections to unknown external IP addresses.