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WEEK_3 · DAY_16 · 1 HOUR

CIM — Common Information Model

How Splunk normalizes every log into 25 standard data models

Splunk Lab

Learning Objectives

  • Understand why CIM exists
  • Map a custom sourcetype to CIM
  • Validate CIM compliance with the Add-on Builder
  • Use tstats against accelerated CIM data models

Module 1 — Why CIM?

Logs come in 1,000 formats. ES needs ONE format to write detections against.

CIM solves this by defining standard fields per category (Authentication, Network_Traffic, Endpoint, Web, Email…).

Module 2 — How CIM Works

Each Data Model has required and recommended fields. You map your sourcetype to them via field aliases, calculated fields, eventtypes, tags.

Splunk Common Information Model add-on (TA) ships acceleration & macros.

Module 3 — CIM Compliance Workflow

Use Splunk Add-on Builder or splunk-cim-validator.

Splunkbase TAs (Technology Add-ons) come pre-CIM-compliant for hundreds of vendors.

Module 4 — tstats on Accelerated DMs

Once accelerated, | tstats summariesonly=t count from datamodel=Authentication runs in seconds across TBs.

Foundation of every ES correlation search.

SPL Queries

Validate Authentication DM
| tstats count from datamodel=Authentication
  by Authentication.sourcetype, Authentication.action
| rename "Authentication.*" as *
| sort - count
// Lists every sourcetype contributing to the Authentication DM and whether action is mapped.

Lab 16 — Validate CIM Compliance

  1. Open Splunk → Search.
  2. Run the Authentication DM validation query.
  3. Identify any sourcetype missing the action field.
  4. Write a fix: eventtype + tag in props.conf.
Launch Lab Workbench

Key Takeaways

  • CIM is the bridge from raw logs to ES detections
  • Use Splunkbase TAs whenever possible
  • tstats on accelerated DMs is the speed of ES