Windows Event Fowarder

This lays out how to create a sbuscription (both source and collector initiated) that collects selected forwarded .evtx event logs from a workstation to a domain controller.

SUMMARY

This shows the process of how to create custom .evtx log files using ecmangen.exe and other utilities present in the Windows Development Kit. The log file(s) created could be used as a destination log for forwarded events.

ENVIRONMENT:

MACHINES:

HOSTNAME	MACHINE IP	OS	REMARKS
MSEDGEWIN10	192.168.150.128	Windows 10 Enterprise Evaluation	Source Machine
WIN-BO2CT95INDP	192.168.150.133	Windows Server 2016	Collector Machine

• The FQDN for WIN-BO2CT95INDP is win-bo2ct95indp.bossmanben.local

ASSUMPTIONS:

1. The Source Machine (MSEDGEWIN10) is part of a Domain Controller (WIN-BO2CT95INDP).

2. This guide uses Security Logs as an example.

3. The steps below will create a subscription that collects Security logs from the Source Machine (MSEDGEWIN10).

PROCEDURE:

1. Start the WinRM service

1. Open PowerShell on the Source Machine (MSEDGEWIN10):

   winrm quickconfig

   Add the Collector Machine to the Source Machine's trustedhosts:

   Set-Item wsman:localhost/client/trustedhosts 192.168.150.133

   Restart the service for changes to take effect:

   Restart-Service WinRM

2. Check if the service is running:

   winrm get winrm/config

   AllowRemoteAccess = true signifies that the service is running.

   ...omitted...
           AllowRemoteAccess = true
       Winrs
           AllowRemoteShellAccess = true
   ...omitted...

3. Test if the Collector Machine (BOSSMANBEN) is reachable using WinRM:

   Test-WSMan WIN-BO2CT95INDP

   wsmid           : http://schemas.dmtf.org/wbem/wsman/identity/1/wsmanidentity.xsd
   ProtocolVersion : http://schemas.dmtf.org/wbem/wsman/1/wsman.xsd
   ProductVendor   : Microsoft Corporation
   ProductVersion  : OS: 0.0.0 SP: 0.0 Stack: 3.0

   WinRM is enabled by default on Windows Server 2012 and up. This is just a measure to check if the Collector Machine is indeed reachable.

ii. Add the Collector Machine to the Event Log Readers groups

In the Source Machine (MSEDGEWIN10):

1. Open the Local Users and Groups:

   • Press Win + R then enter lusrmgr.msc

2. Navigate to Local Users and Groups (Local) > Groups:

   1. Right-click Event Log Readers and select Properties

   2. Select Add...

3. Select Object Types... then check the box, Computers

4. Enter the object names to select -- "WIN-BO2CT95INDP"

   • Select Check Names for good measure.

5. Select OK when done.

iii. Create Subscriptions using Event Viewer

In the Collector Machine (WIN-BO2CT95INDP):

Open the Event Viewer -- Press Win + R then enter gpedit eventvwr.msc and on the left panel, right-click on Subscriptions then select Create Subscription...

1. Subscription Name -- Remote Security Logs

2. Description -- Security Logs from the Domain Computer, MSEDGEWIN10

3. Destination log -- Forwarded Events

   • Custom logs could be created but Forwarded Events is selected by default.

   • Click here to create custom logs.

4. Select Subscription type and source computers:

   If you choose Collector initiated, then select Select Computers...

   1. Select Add Domain Computers...

   2. Enter the object name to select -- "MSEDGEWIN10"

   3. Select Check Names for good measure.

   4. Select OK

   5. Select Test for good measure.

   6. Select OK

   For Source initiated, select Select Computer Groups... then do the following extra steps on the Source Machine

   1. Press Win + R then enter gpedit.msc

      1. Navigate to Computer Management > Administrative Templates > Windows Components > Event Forwarding

      2. Right-click on Configure target Subscription Manager then select Edit

      3. Choose Enabled

      4. Under Options, beside SubscriptionManagers, press Show...

      5. Enter Server= http://win-bo2ct95indp.bossmanben.local:5985 /wsman/SubscriptionManager/WEC, Refresh=30

      6. Press OK

      7. Press OK

   2. Open PowerShell or cmd the run gpupdate /force

   For Source initiated, do the following on the Collector Machine (WIN-BO2CT95INDP)

   1. Open PowerShell or cmd then run wecutil quick-config

5. Select Select Events...:

   1. Logged -- "Any time"

   2. Event level -- Critical, Error, Information, Warning

   3. Choose By log -- Windows -> Security

   4. Filter Event IDs -- 4624, 4657, 4688, 4698, 4720, 4722, 4724, 4732, 4738, 4769

   5. Select OK

6. Select Advanced...:

   1. User Account -- Choose Machine Account

   2. Event Delivery Optimization -- Choose Minimize Latency

   3. Select OK

   OPTION	DESCRIPTION	INTERVAL
   Normal	Does not conserve bandwidth	15 minutes via pull delivery
   Minimize Bandwidth	Bandwidth for delivery is controlled	6 hours via push delivery
   Minimize Latency	Delivery with minimal delay	30 seconds via push delivery
7. Select OK

8. Right-click on the newly created subscription then select Runtime Status:

   [MSEDGEWIN10.bossmanben.local] - Error - Last retry time: 7/17/2019 8:27:52 PM. 
   Code (0x138C): <f:ProviderFault provider="Event Forwarding Plugin" path="C:\Windows\system32\wevtfwd.dll"

In the Source Machine (WIN-BO2CT95INDP)

1. Run wevtutil:

   wevtutil get-log Security

   name: Security
   enabled: true
   type: Admin
   owningPublisher:
   isolation: Custom
   channelAccess: O:BAG:SYD:(A;;0xf0005;;;SY)(A;;0x5;;;BA)(A;;0x1;;;S-1-5-32-573)
   logging:
     logFileName: %SystemRoot%\System32\Winevt\Logs\Security.evtx
     retention: false
     autoBackup: false
     maxSize: 20971520
   publishing:
     fileMax: 1

2. Add the Network Service Account (S-1-5-20) to the channelAccess field:

   wevtutil set-log Security /ca:"O:BAG:SYD:(A;;0xf0005;;;SY)(A;;0x5;;;BA)(A;;0x1;;;S-1-5-32-573)(A;;0x1;;;S-1-5-20)"

   • WinRM runs under the Network Service Account which had no access to the Security Logs

Going back to the Collector Machine (WIN-BO2CT95INDP)

1. Go to the Event Viewer:

   • Press Win + R then enter gpedit eventvwr.msc

2. On the left panel, go to Subscriptions then select the recently created subscription

3. On the right panel, under the subscription name, select Retry

4. Right-click on the recently created subscription then select Runtime Status:

   [MSEDGEWIN10.bossmanben.local] - Active - : No additional status.

   • An Event with ID 100 (Name="SubscribeSuccess") will appear on Microsoft-Windows-Event-ForwardPlugin/Operational in the Source Machine (MSEDGEWIN10)

Finally, Wait for logs to be sent to the Forwarded Events logs

NOTE(S):

• TImestamps are preserved

• Log contents are preserved

REFERENCES:

- https://www.vkernel.ro/blog/how-to-configure-windows-event-log-forwarding?fbclid=IwAR1bQ9VpgL--PWaqvEWcJBduR3xJ2UnBBhZmO7UGef-NXcKN9PCINZ3gmQ0
- https://www.itprotoday.com/strategy/q-what-are-some-simple-tips-testing-and-troubleshooting-windows-event-forwarding-and?fbclid=IwAR3ceGoJU-jgkD2U_rVo2FmQee5M0spvE85lZRVw0FHv4YFTphLaX-5JJe8
- https://rockyprogress.wordpress.com/2011/12/04/security-event-log-collection-from-a-domain-controller/?fbclid=IwAR01Puy9Wvr4eCQeV828raqfLesYJwVTw_8EAmDgvJIKYBVWoaT3giv24PA
- https://blogs.technet.microsoft.com/supportingwindows/2016/07/18/setting-up-a-source-initiated-subscription-on-an-event-collector-computer/?fbclid=IwAR2JagIePrComWaIcZknK_92Igakb4_jvnrmJJnGpZlFGnms_2PM7z6trJc