Windows Event logging into graylog


(Nav) #1

Hi Folks,

I have successfully configured graylog with windows server using nxlog. I am able to see the logs coming in graylog. But there are some issues.

  1. Windows log send data as raw text and xml.
  2. graylog is able to pickup xml just fine and index the data in the fields and raw text goes into full_message and message fields.
  3. some of the xml data is not in shape. kindly check the attached screenshot of field Failure reason.

How can i extract the Failure Reason and put inside another field?
I am trying using extractors but so far no luck.


(Jochen) #2

What’s your NXLOG configuration?


(Nav) #3

Here is the nxlog config file. I am using collector to push the nxlog config to the nodes.

define ROOT C:\Program Files (x86)\nxlog

<Extension gelf>
  Module xm_gelf
</Extension>

<Processor 5a71798664058a23adcfc294-buffer>
  Module pm_buffer
  MaxSize 16384
  Type Mem
</Processor>



Moduledir %ROOT%\modules
CacheDir %ROOT%\data
Pidfile %ROOT%\data\nxlog.pid
SpoolDir %ROOT%\data
LogFile %ROOT%\data\nxlog.log
LogLevel INFO

<Extension logrotate>
    Module  xm_fileop
    <Schedule>
        When    @daily
        Exec    file_cycle('%ROOT%\data\nxlog.log', 7);
     </Schedule>
</Extension>




<Input 5a71798664058a23adcfc294>
	Module im_msvistalog
	PollInterval 1
	SavePos	True
	ReadFromLast True
	Channel Security
	Query <QueryList>\
    <Query Id="0">\
    <Select Path="Security">*[System[(EventID=4625)]]</Select>\
    <Select Path="Security">*[System[(EventID=4740)]]</Select>\
    <Select Path="Security">*[System[(EventID=4771)]]</Select>\
    </Query>\
    </QueryList>
</Input>




<Output 5a71779164058a23adcfc06b>
	Module om_tcp
	Host 172.17.1.87
	Port 5044
	OutputType  GELF_TCP
	Exec $short_message = $raw_event; # Avoids truncation of the short_message field.
	Exec $gl2_source_collector = 'e6e5e646-e79c-4b46-8422-29503febae7b';
	Exec $collector_node_id = server-pdc';
	Exec $Hostname = hostname_fqdn();
</Output>


<Route route-0>
  Path 5a71798664058a23adcfc294 => 5a71798664058a23adcfc294-buffer => 5a71779164058a23adcfc06b
</Route>

(Jochen) #4

All select statements in a XPath query have to match.
Try splitting the XPath query into multiple queries or use other means of filtering the Event IDs.

Please refer to the following pages for details:


(Nav) #5

The queries are working fine as I am receiving the data. the question is how to get the fields in full message into graylog. There is some variation in full message data and xml data.


#6

You can make a regex extractor for the missing fields. For example:

Match only when full_message contains FailureReason">

Regex something like "FailureReason"\>(>?([^<]*))\</Data\>

(add quote characters \ wherever needed)


(Nav) #7

Would it be possible to extract the line where failure reason: keyword comes in? Coz failure reason could be different even though it’s a same event.


#8

If you have that in the full message, then you can extract that.

Try something like

Failure Reason:\s+(>?([^\s].*)$)


(Nav) #9

Thanks Jtkarvo, the regular expression did the trick.


(system) #10

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