Splunk Search

Using Machine Learning Toolkit to detect auth abuse

patpro
Path Finder

Hello,

I’m trying to tune Machine Learning Toolkit in order to detect authentication abuse on a web portal (based upon Lemon LDAP-NG).

My logs look like this:

(time/host/... header) client=(IP address) user=(login) sessionID=(session-id) mail=(user email address) action=(various statuses: connected / non-existent user / wrong pwd…)
 
I would like to train the Machine Learning Toolkit so that I can detect anomalies. Those anomalies can be:
- that client has made auth attempts for an unusual number of logins
- that client has made auth attempts for both non-existing and existing users
- …
 
So far it fails hard.
 
I’ve trained a model like this on approx. a month of data:

 

index="webauth" ( TERM(was) TERM(not) TERM(found) TERM(in) TERM(LDAP) ) OR TERM(connected) OR TERM(credentials) linecount=1 | rex "action=(?<act>.*)" | eval action=case(match(act,".* connected"), "connected", match(act,".* was not found in LDAP directory.*"), "unknown", match(act, ".* credentials"),"wrongpassword") | bin span=1h _time | eventstats dc(user) AS dcUsers, count(user) AS countUsers BY client,_time,action|search dcUsers>1|stats values(dcUsers) AS DCU,values(countUsers) AS CU BY client,_time,action| eval HourOfDay=strftime(_time,"%H") 
| fit DensityFunction CU by "client,DCU" as outlier into app:TEST

 

 
Then I’ve tested the model on another time interval where I know there is a big anomaly, by replacing the fit directive by "apply (model-name) threshold=(various values)".
No result.
 
So I guess I’m not on the right track to achieve this. Any help appreciated!
 
Tags (1)
0 Karma
Get Updates on the Splunk Community!

CX Day is Coming!

Customer Experience (CX) Day is on October 7th!! We're so excited to bring back another day full of wonderful ...

Strengthen Your Future: A Look Back at Splunk 10 Innovations and .conf25 Highlights!

The Big One: Splunk 10 is Here!  The moment many of you have been waiting for has arrived! We are thrilled to ...

Now Offering the AI Assistant Usage Dashboard in Cloud Monitoring Console

Today, we’re excited to announce the release of a brand new AI assistant usage dashboard in Cloud Monitoring ...