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!

Splunk Enterprise Security 8.0.2 Availability: On cloud and On-premise!

A few months ago, we released Splunk Enterprise Security 8.0 for our cloud customers. Today, we are excited to ...

Logs to Metrics

Logs and Metrics Logs are generally unstructured text or structured events emitted by applications and written ...

Developer Spotlight with Paul Stout

Welcome to our very first developer spotlight release series where we'll feature some awesome Splunk ...