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
Got questions? Get answers!

Join the Splunk Community Slack to learn, troubleshoot, and make connections with fellow Splunk practitioners in real time!

Meet up IRL or virtually!

Join Splunk User Groups to connect and learn in-person by region or remotely by topic or industry.

Get Updates on the Splunk Community!

Why Splunk Customers Should Attend Cisco Live 2026 Las Vegas

Why Splunk Customers Should Attend Cisco Live 2026 Las Vegas     Cisco Live 2026 is almost here, and this ...

What Is the Name of the USB Key Inserted by Bob Smith? (BOTS Hint, Not the Answer)

Hello Splunkers,   So you searched, “what is the name of the usb key inserted by bob smith?”  Not gonna lie… ...

Automating Threat Operations and Threat Hunting with Recorded Future

    Automating Threat Operations and Threat Hunting with Recorded Future June 29, 2026 | Register   Is your ...