2 Replies Latest reply on May 20, 2015 8:32 AM by eq-rstrong

    Correlation Rule - How to look for specific domain suffix

    eq-rstrong

      Hello,

       

      I'm looking for some assistance in creating a correlation rule that is able to look for a specific domain suffix like ".tor2web., .pw, etc" within the Domain or Web_Domain fields. I'd rather not dynamically generate a watch list then apply it to a correlation rule as its not very efficient.

       

      Has anyone else been able to create a correlation rule by using a "contains" type operator?

       

      Thanks,

      Rob.

        • 1. Re: Correlation Rule - How to look for specific domain suffix
          andy777

          Hi Rob,

           

          I don't believe regex-based correlation parameters are permitted. Another way to accomplish this - aside from a watchlist, which does support regex, would be to adjust the parsing rule so that the TLD would be additionally parsed into its own field which could be indexed, manipulated and used for rules. Thanks.

           

          Andy

          • 2. Re: Correlation Rule - How to look for specific domain suffix
            eq-rstrong

            Thanks for the response Andy.

             

            For those interested in the technical details, I created two additional custom types (TLD1, TLD2) which I have indexed. I run a WebSense proxy and found the existing signature ID that parses the logs received (1018095), copied it and added the following regular expressions:

             

            domain\x3d\x22[^\x22]+(\.[^\x22\d]+)\x22 - Maps to TLD1

            domain\x3d\x22[^\x22]+(\.[\d\w][^\x22]+\.[^\x22\d]+)\x22 - Maps to TLD2

             

            It's important to 'disable' the original 'Websense_Ent Websense SQL Event' rule (1018095).

             

            I now have the ability to specifically chart 'suspicious' domains (.io, .pw, co.vu, .info, etc) as well as more effectively filter out known good sub-domains (.gstatic.com, .googleapis.com, .youtube.com, etc).

             

            Hope this helps other people.

             

            Cheers,

            Rob.