[Bro] ACTION_ALARM and ACTION_EMAIL

Azoff, Justin S jazoff at illinois.edu
Thu Jan 28 05:46:44 PST 2016


Ah, I made a common error. The redef line is a regular statement(compared to something like an 'if' or 'export' block) and it needs a ; at the end. The final line needs to be

};

Bro complains about controllee.bro because it is still expecting a ; and it is the next file that is parsed.

-- 
- Justin Azoff

> On Jan 28, 2016, at 6:20 AM, Tim Desrochers <tgdesrochers at gmail.com> wrote:
> 
> When trying what you suggested I get the following output from broctl check:
> 
> error in /opt/bro/share/bro/policy/frameworks/control/controllee.bro, line 15: syntax error, at or near "module"
> 
> At the bottom of my local.bro I added:
> redef Notice::emailed_types += {
>   FTP::Bruteforcing,
>   FTP::Site_Exec_Success,
>   HTTP::SQL_Injection_Attacker,
>   HTTP::SQL_Injection_Victim,
>   SMTP::Blocklist_Error_Message,
>   SMTP::Blocklist_Blocked_Host,
>   SMTP::Suspicious_Origination,
>   SSH::Password_Guessing,
>   SSH::Login_By_Password_Guesser,
>   }
> 
> Any reason why broctl is finding an error in the controllee.bro script. 
> 
> On Wed, Jan 6, 2016 at 10:50 AM, Azoff, Justin S <jazoff at illinois.edu> wrote:
> I'm not sure about #2, but for 1 and 3 there is an easy way to do this with the default configuration.  The notice framework has this as the notice policy:
> 
> hook Notice::policy(n: Notice::Info) &priority=10
>     {
>     if ( n$note in Notice::ignored_types )
>         break;
> 
>     if ( n$note in Notice::not_suppressed_types )
>         n$suppress_for=0secs;
>     if ( n$note in Notice::alarmed_types )
>         add n$actions[ACTION_ALARM];
>     if ( n$note in Notice::emailed_types )
>         add n$actions[ACTION_EMAIL];
> 
>     if ( n$note in Notice::type_suppression_intervals )
>         n$suppress_for=Notice::type_suppression_intervals[n$note];
> 
>     # Logging is a default action.  It can be removed in a later hook if desired.
>     add n$actions[ACTION_LOG];
>     }
> 
> Those tables are all setup to make it easy to toggle actions:
> 
>     ## Ignored notice types.
>     const ignored_types: set[Notice::Type] = {} &redef;
>     ## Emailed notice types.
>     const emailed_types: set[Notice::Type] = {} &redef;
>     ## Alarmed notice types.
>     const alarmed_types: set[Notice::Type] = {} &redef;
>     ## Types that should be suppressed for the default suppression interval.
>     const not_suppressed_types: set[Notice::Type] = {} &redef;
> 
> So you simply need something like this in your local.bro:
> 
> redef Notice::emailed_types += {
>     HTTP::SQL_Injection_Attacker,
>     HTTP::SQL_Injection_Victim,
> }
> 
> If you do need to do anything more complicated, you can use your own Notice::policy and add whatever logic you want.
> 
> To not get multiple emails for the same notice you need to ensure that the notice has the $identifier set that uniquely identifies the notice.  This is minimally something like cat(id$orig_h).  If you look at any of the scripts in policy/ you can see how they do this.
> 
> 
> 
> --
> - Justin Azoff
> 
> > On Jan 6, 2016, at 10:33 AM, Tim Desrochers <tgdesrochers at gmail.com> wrote:
> >
> > I have my sensor set up to email me notices with:
> >
> > hook Notice::policy(n: Notice::Info)
> >             {
> >             add n$actions[Notice::ACTION_EMAIL];
> >             }
> >
> > If I understand correct this will email me upon any entry in the notice.log.  Is there a way to:
> > 1. only get specific items emailed upon entry
> > 2. get the rest of notice.log entries emailed with ACTON_ALARM in the alarm-mail.txt and have that ignore anything that was previously emailed.
> > 3. Only get one notice email per alert?
> >
> > What I am doing is in the /opt/bro/share/bro/intel folder creating different folders with IOS's I want the intel framework to look over and I am using meta.do_notice to send the items of importance to the notice log.
> >
> > Excuse my ignorance with this subject I am just now trying to get things emailed out efficiently to reduce some noise and redundancy my analysts are seeing.
> > _______________________________________________
> > Bro mailing list
> > bro at bro-ids.org
> > http://mailman.ICSI.Berkeley.EDU/mailman/listinfo/bro
> 
> 




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