Splunk Enterprise Security

Find anomalous network traffic of a user

narisree1
Loves-to-Learn Everything

Hi team,

I m trying to find network traffic of a user and classify it as high or normal based on avg and stdev calculations

QUERY :
index="pan_logs" sourcetype="pan:traffic" user!=unknown | stats sum(bytes) as bytes by _time,user |eval MB = round(bytes/1024/1024,4)|bin span=1d _time | stats avg(MB) as avg stdev(MB) as stdv by user,_time|eval avg = round(avg,4) , stdv = round(stdv,4) | eval Volume_Type= if((avg+2*stdv)> MB , "HIGH" , "NORMAL

However the avg and stdev calculation is wrong here as it collects per day basis and not when i keep it for last 7 days.

0 Karma

codebuilder
Influencer

Splunk has built in functionality to make this much easier. Try using "anomalies" and/or "anomalousvalue"

https://docs.splunk.com/Documentation/Splunk/8.0.1/SearchReference/Anomalies

https://docs.splunk.com/Documentation/Splunk/8.0.1/SearchReference/Anomalousvalue

----
An upvote would be appreciated and Accept Solution if it helps!
0 Karma

narisree1
Loves-to-Learn Everything

Thanks for the response.However i am not sure of the threshold value to be set as it can change user to user hence i calculated it based on avg and stdev .i understand we can use streamstats command but i am unable to calculate avg for last 7 days as i had already bin for 1 day at start.

0 Karma
Get Updates on the Splunk Community!

Stay Connected: Your Guide to May Tech Talks, Office Hours, and Webinars!

Take a look below to explore our upcoming Community Office Hours, Tech Talks, and Webinars this month. This ...

They're back! Join the SplunkTrust and MVP at .conf24

With our highly anticipated annual conference, .conf, comes the fez-wearers you can trust! The SplunkTrust, as ...

Enterprise Security Content Update (ESCU) | New Releases

Last month, the Splunk Threat Research Team had two releases of new security content via the Enterprise ...