Hi Dan,

Thank you for taking time to correct my local rule. 

The reason why I want to write a custom decoder and rule to parse Windows 
events is that I need to extract useful and correct values from the log 
such as the event id, extra_data (what happened), and the actual user 
account name. Wrong or useless values will be extracted as extra_data, 
user, and system_name if default is in use. As the result, a fix of the 
default behavior is needed as I noticed. 

I also want to configure an active response to send an email notification 
and see if a correlation of events can be done to manipulate alert 
notifications. It seems to me that by going with the existing Windows 
default what I planned to accomplish cannot be fulfilled.

I saw from the test output that the alert level stays 9 but not 5 if I use 
windows but not windows-4740 as a decoder. What's a proper way to achieve 
what I planned to do? Thanks,  

On Monday, October 21, 2013 5:39:08 PM UTC-7, tww0101 wrote:
>
> In an attempt to get custom Windows decoder and rules working, I came up 
> with the following decoder and rule:
>
> In local_rules.xml:
>
> <group name="windows-account-lockout">
>   <rule id="100010" level="5">
>      <decoded_as>windows-4740</decoded_as>
>      <description>windows-account-lockout</description>
>   </rule>
> </group>
>
> In decoder.xml:
>
> <decoder name="windows-4740">
>   <type>windows</type>
>  <parent>windows</parent>
> <regex offset="after_parent">^\.+: (\w+)\((\d+)\):\.+</regex>
> <regex>0x3a1\s+(\.+):\s+Security ID:\.+Account Name:\s+(\S+)</regex>
> <order>status, id, extra_data, user</order>
>  <fts>name, location, user, system_name</fts>
> </decoder>
>
> Here is a sample Windows event log that was used for testing:
>
> WinEvtLog: Security: AUDIT_SUCCESS(4740): XXXXXXXXXXXXXX: (no user): no 
> domain: XXXXXXX: XXXXXXX    message: A user account was locked out.  
> Subject:  Security ID:  XXXXX  Account Name:  XXX  Account Domain:  
> EXAMPLE  Logon ID:  0x3a1  Account That Was Locked Out:  Security ID:  
> XXXXXXXXXXXXXXX  Account Name:  jking  Additional Information:  XXXXX:
>
> /opt/ossec/ossec-logtest -d
>
> ...
> 2013/10/21 14:55:40 1 : rule:100010, level 5, timeout: 0
> ...
> ...
>
> **Phase 2: Completed decoding.
>        decoder: 'windows'
>        status: 'AUDIT_SUCCESS'
>        id: '4740'
>        extra_data: ' Account That Was Locked Out'
>        dstuser: 'jking'
>
> **Phase 3: Completed filtering (rules).
>        Rule id: '18116'
>        Level: '9'
>        Description: 'User account locked out (multiple login errors).'
> **Alert to be generated.
>
>
> It seems to me that my decoder is working. However, why rule 18116 is 
> still in use? How can I bypass default msauth rules? Can someone please 
> help? Thanks,
>

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