topic Re: Splunk ES Correlation Search Not Firing [When it should] in Alerting

Splunk ES Correlation Search Not Firing [When it should]

BrianKJr — Sat, 16 Jan 2021 20:53:39 GMT

Hello,

So I am working on a CS for Enterprise Security that -- when run manually -- it returns results; however, when its scheduled to run it does not return anything.

I've looked in the _internal index and found that:

0 suppressions are taking effect
0 results are returned
All searches are ran successfully

I've looked in the notable's index and confirmed that 0 alerts are firing.

The CS is running as ADMIN within the application context of Enterprise Security.

This is the search:

index=cylance_protect sourcetype=threat
| eval FirstFound=split('First Found'," ")
| eval FirstFoundDate=mvindex(FirstFound,0)
| eval FirstFoundDate_epoch=strptime(FirstFoundDate, "%m/%d/%Y")
| eval currentTime=now()
| eval currentTime=strftime(currentTime, "%m/%d/%Y")
| eval currentTime_epoch=strptime(currentTime, "%m/%d/%Y")
| eval CreatedDaysAgo=(currentTime_epoch-FirstFoundDate_epoch)/86400
| eval CreatedDaysAgo=round(CreatedDaysAgo)
| search CreatedDaysAgo < 2
| table _time FirstFound CreatedDaysAgo DeviceName Tenant user action "Cylance Score" signature "Detected By" "Ever Run" "File Name" file_path file_hash

Are the eval statements causing this issue? I used the above logic to ONLY return 'new' Cylance detections within the last 1 day.

Re: Splunk ES Correlation Search Not Firing [When it should]

scelikok — Sat, 16 Jan 2021 21:15:59 GMT

Hi @BrianKJr,

The problem may be the time range setting on your correlation search. Are you using the same time-range on manual testing? Maybe you should increase time-range on your correlation search.

If this reply helps you an upvote is appreciated.

Re: Splunk ES Correlation Search Not Firing [When it should]

BrianKJr — Sun, 17 Jan 2021 15:42:23 GMT

Hello @scelikok

Yes the search runs every 5 minutes, and looks back 1 hour. Today it should have generated three unique alerts.

Its been running for a couple days at this point, and the base search has matched 10 + events. We've received 0 though.

Re: Splunk ES Correlation Search Not Firing [When it should]

BrianKJr — Tue, 19 Jan 2021 18:51:55 GMT

After further troubleshooting the time range WAS the issue due to API schedule for threats being forwarded to Splunk.. The API through Cylance / Splunk will need to be looked at because its not sending logs as often as it should be.

The solution for the interim is to extend the time range from 2 hours to 12 hours.

Thanks for responding 🙂