[Zeek] Creating a module and accessing an event in another script

Merril Mathew merril.mathew at baby2body.com
Thu Jun 6 10:02:50 PDT 2019


Please find attached. It complains on the first if statement that auth_success is missing. At line 14 for !rec$auth_success.

Merril.
> On 6 Jun 2019, at 17:56, Justin Azoff <justin at corelight.com> wrote:
> 
> What does your current script look like?
> 
> On Thu, Jun 6, 2019 at 12:46 PM Merril Mathew <merril.mathew at baby2body.com <mailto:merril.mathew at baby2body.com>> wrote:
> Hi Justin,
> 
> Thanks again. I made the changes you sent and I am getting this error on reporter.log. “ 1559839456.472514       Reporter::ERROR field value missing [SSH::rec$auth_success]     /usr/local/bro/share/bro/site/alert_ssh_attempt.bro, line 22” 
> 
> But it definitely	returns auth_success=F when running on .pcap. I assume auth_success will be T when I ssh into the box?
> 
> Kind regards,
> Merril.
> 
>> On 6 Jun 2019, at 17:22, Justin Azoff <justin at corelight.com <mailto:justin at corelight.com>> wrote:
>> 
>> email_ssh_attempt.bro is not required at all because you already added Login_Attempted to Notice::emailed_types in the other script.
>> 
>> Your other script is slightly broken because in the case of unknown result the field is not present, so your script needs to look like this.
>> 
>> event log_ssh(rec: Info) &priority=5
>> {
>>     if(!rec?$auth_success) {
>>         NOTICE([$note=SSH::Login_Attempted, $msg=fmt("Unknown")]);
>>     }
>>     else if(rec$auth_success == F) {
>>         NOTICE([$note=SSH::Login_Attempted,
>>            $msg=fmt("SSH login attempted from %s, %s many times and failed", rec$client, rec$auth_attempts)]);
>>     } else {
>>         NOTICE([$note=SSH::Login_Attempted,
>>            $msg=fmt("SSH login attempted from %s, %s many times and succeeded", rec$client, rec$auth_attempts)]);
>>     }
>> }
>> 
>> if you look at your reporter.log you should see it filled with errors like this:
>> 
>> Reporter::ERROR	field value missing [SSH::rec$auth_success]  alert_ssh_attempt_new.bro, line 14
>> 
>> 
>> 
>> 
>> On Thu, Jun 6, 2019 at 12:10 PM Merril Mathew <merril.mathew at baby2body.com <mailto:merril.mathew at baby2body.com>> wrote:
>> Hi All,
>> 
>> I cannot figure out why the Notice doesn’t behave as expected on live traffic. I am now trying to make it work with SSH (log_ssh) event as previous attempt on ssh_auth_result lead me nowhere. If I raise the NOTICE function  just after the log_ssh event from a script it sends me email on live traffic. However if I use the NOTICE function inside IF, ELSE IF, ELSE conditionals for auth_success boolean then it does not send me emails. Anyone see what I am doing wrong? I couldn’t figure it out from Notice documentation.
>> 
>> Please find attached the scripts for reference.
>> 
>> Kind regards,
>> Merril.
>> 
>>> On 5 Jun 2019, at 18:39, Justin Azoff <justin at corelight.com <mailto:justin at corelight.com>> wrote:
>>> 
>>> that script should generally work, but it was a lot more complicated than it needed to be to accomplish what you are trying to do.  Here is a much simplified version.
>>> 
>>> The only thing to keep in mind is that since you are using zeek_init to setup the log stream this won't work on bro or a small number of zeek builds from right after the rename.  There are no released versions of zeek so I don't know when you built it.  Using bro_init is backwards compatible and is probably better for now.
>>> 
>>> On Wed, Jun 5, 2019 at 12:46 PM Merril Mathew <merril.mathew at baby2body.com <mailto:merril.mathew at baby2body.com>> wrote:
>>> Hi Justin,
>>> 
>>> I can confirm that attached scripts does not send me email on live traffic or create a log under $PREFIX/logs/current. But it does create notice.log and a SSHAttempt.log when running pcap. I can also confirm that send mail set up is working as I have received emails from zeek from other scripts.
>>> 
>>> Kind regards,
>>> Merril.
>>> 
>>> 
>>> 
>>>> On 5 Jun 2019, at 17:20, Justin Azoff <justin at corelight.com <mailto:justin at corelight.com>> wrote:
>>>> 
>>>> On Wed, Jun 5, 2019 at 12:11 PM Merril Mathew <merril.mathew at baby2body.com <mailto:merril.mathew at baby2body.com>> wrote:
>>>> Hi Justin,
>>>> 
>>>> Thanks. But it did not work for me.
>>>> 
>>>> Did not work how?  Did you post the version of the script that didn't work? 
>>>> 
>>>> -- 
>>>> Justin
>>> 
>>> 
>>> 
>>> -- 
>>> Justin
>>> <main.zeek>
>> 
>> 
>> 
>> -- 
>> Justin
> 
> 
> 
> -- 
> Justin

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