Splunk Enterprise Security

ES Tuning Question

edwardrose
Contributor

Hello All,

I am working on tuning the Network-Unroutable Host Activity -Rule search and we are trying to exclude our VPN networks and DNS hosts that are sending data to 192.0.0.0 from the search. I thought I could run a loop for every IP address of our dns servers. Here is what I added to the fully blown out search but it does not seem to be working like I thought it would.

| tstats prestats=true local=false summariesonly=true allow_old_summaries=true count,values(sourcetype) from datamodel=Network_Traffic.All_Traffic where All_Traffic.action=allowed by All_Traffic.src,All_Traffic.dest 
| rename "All_Traffic.*" as "*" 
| tstats prestats=true local=false summariesonly=true allow_old_summaries=true append=true count,values(sourcetype) from datamodel=Intrusion_Detection.IDS_Attacks by IDS_Attacks.src,IDS_Attacks.dest 
| rename "IDS_Attacks.*" as "*" 
| tstats prestats=true local=false summariesonly=true allow_old_summaries=true append=true count,values(sourcetype) from datamodel=Web.Web by Web.src,Web.dest 
| rename "Web.*" as "*" 
| stats count,values(sourcetype) as sourcetype by src,dest 
| lookup local=true bogonlist_lookup_by_cidr ip AS "src" OUTPUTNEW is_bogon AS "src_is_bogon",is_internal AS "src_is_internal" 
| lookup local=true bogonlist_lookup_by_cidr ip AS "dest" OUTPUTNEW is_bogon AS "dest_is_bogon",is_internal AS "dest_is_internal" 
| search (NOT dest=169.254.* NOT src=169.254.* ((dest_is_internal!=true dest_is_bogon=true) OR (src_is_internal!=true src_is_bogon=true))) 
| search (NOT dest=[| inputlookup mentor_assets.csv | search nt_host="*-ddi-*" | table ip] NOT src=[| inputlookup mentor_assets.csv | search nt_host="*-ddi-*" | table ip]  ((dest_is_internal!=true dest_is_bogon=true) OR (src_is_internal!=true src_is_bogon=true)))
| eval bogon_ip=if(((dest_is_bogon == "true") AND (dest_is_internal != "true")),dest,bogon_ip), bogon_ip=if(((src_is_bogon == "true") AND (src_is_internal != "true")),src,bogon_ip) 
| fields + sourcetype, src, dest, bogon_ip

I added the following line:

| search (NOT dest=[| inputlookup mentor_assets.csv | search nt_host="*-ddi-*" | table ip] NOT src=[| inputlookup mentor_assets.csv | search nt_host="*-ddi-*" | table ip]  ((dest_is_internal!=true dest_is_bogon=true) OR (src_is_internal!=true src_is_bogon=true)))

But like I stated it does not seem to be working like I thought it should. Any help would be appreciated.

Thanks
ed

0 Karma
Get Updates on the Splunk Community!

Announcing Scheduled Export GA for Dashboard Studio

We're excited to announce the general availability of Scheduled Export for Dashboard Studio. Starting in ...

Extending Observability Content to Splunk Cloud

Watch Now!   In this Extending Observability Content to Splunk Cloud Tech Talk, you'll see how to leverage ...

More Control Over Your Monitoring Costs with Archived Metrics GA in US-AWS!

What if there was a way you could keep all the metrics data you need while saving on storage costs?This is now ...