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!

Upcoming Webinar: Unmasking Insider Threats with Slunk Enterprise Security’s UEBA

Join us on Wed, Dec 10. at 10AM PST / 1PM EST for a live webinar and demo with Splunk experts! Discover how ...

.conf25 technical session recap of Observability for Gen AI: Monitoring LLM ...

If you’re unfamiliar, .conf is Splunk’s premier event where the Splunk community, customers, partners, and ...

A Season of Skills: New Splunk Courses to Light Up Your Learning Journey

There’s something special about this time of year—maybe it’s the glow of the holidays, maybe it’s the ...