Tag Archive: SIEM

Windows Event Forward and Custom Logs

First of all, this post is more about configuring custom event channels than configure WEF.

 

There is more than one way to work with event logs and the most important is to start working with event logs.

Some of the benefits is one place to find the logs for multiple systems and if someone clears, for example, the security log it’s important that you can find the log events before that happened and have alerts triggered on the clearing event.

Using the WEC (Windows Event collector) service is a free option and one of the most frequent used way to gather logs from Windows Clients.

So where do these events end up?

 

Windows Event Forward uses WinRM to forward the logs from the source to the server which runs the Windows Event Collector Service.

There are 2 different options where one option is to let the WEC server to connect to the client and poll the events and the other options is to let the client to push the events to the WEC server.

This is configured in the subscription part in Event Viewer

Besides the Subscription types you also must configure the Destination log (Default Forwarded Events) and select which events will be forwarded.

There are a few git projects for events in xml(xpath) format which you can use to automatically update the events.

 

There are more than security people which wants to be able to forward events.

IT operations and endpoint management teams would benefit from WEF by being able to collect errors and other events that might help with troubleshooting.

If you are about to publish new applocker rules you could set them in Audit mode and collect and analyze information where the rules would impact on a user.

Since we have multiple user cases for WEF you may want to separate the logs into different logs.

Security people maybe don’t want the support-.log to fill their selections of security related events.

You may want to forward the security logs into a SIEM solution like Splunk or QRADAR and don’t want to waist SIEM data license with non-security events.

 

To achieve this, we create a custom log.

Using Ecmangen.exe (provided in one of the Windows 10 SDKs, beware of that this tool is removed from the latest releases)

Save the output to c:\temp\WEF and run the following commands

“C:\Program Files (x86)\Windows Kits\10\bin\x64\mc.exe” C:\temp\wef\WEFEvents.man

“C:\Program Files (x86)\Windows Kits\10\bin\x64\mc.exe” -css WEFEvents.DummyEvent C:\temp\wef\WEFEvents.man

 “C:\Program Files (x86)\Windows Kits\10\bin\x64\rc.exe” C:\temp\wef\WEFEvents.rc

 “C:\Windows\Microsoft.NET\Framework64\v4.0.30319\csc.exe” /win32res:C:\temp\wef\WEFEvents.res /unsafe /target:library /out:C:\temp\wef\WEFEvents.dll C:\temp\wef\WEFEvents.cs

Copy the WEFEvents.dll and WEFEvents.man to c:\windows\system32 and register with:

wevtutil im c:\Windows\system32\WEFEvents.man

 

You will now be able to use these logs for WEF.

You can have, for example, one for servers one for clients. One with a SPLUNK forwarder and one inserted to a database with a nice custom interface which suites your need depending of what you have.