analyzing-windows-event-logs-in-splunk

name	analyzing-windows-event-logs-in-splunk
description	Analyzes Windows Security, System, and Sysmon event logs in Splunk to detect authentication attacks, privilege escalation, persistence mechanisms, and lateral movement using SPL queries mapped to MITRE ATT&CK techniques. Use when SOC analysts need to investigate Windows-based threats, build detection queries, or perform forensic timeline analysis of Windows endpoints and domain controllers.
domain	cybersecurity
subdomain	soc-operations
tags	["soc","splunk","windows-events","sysmon","event-logs","mitre-attack","active-directory"]
version	1.0
author	mahipal
license	Apache-2.0
d3fend_techniques	["Restore Access","Password Authentication","Biometric Authentication","Strong Password Policy","Restore User Account Access"]
nist_csf	["DE.CM-01","DE.AE-02","RS.MA-01","DE.AE-06"]

Analyzing Windows Event Logs in Splunk

When to Use

Use this skill when:

• SOC analysts investigate alerts related to Windows authentication, process execution, or AD changes
• Detection engineers build SPL queries for Windows-based threat detection
• Incident responders need forensic timelines of Windows endpoint or domain controller activity
• Periodic threat hunting targets Windows-specific ATT&CK techniques

Do not use for Linux/macOS endpoint analysis or network-only investigations.

Detection Gaps & Validation

• Index/sourcetype drift: these queries assume index=wineventlog and index=sysmon, but forwarders often land Security logs in a different index or under sourcetype="WinEventLog:Security" vs XmlWinEventLog:Security. The XML sourcetype exposes fields differently (EventCode may be EventID, TargetUserName nested in EventData). Run | tstats count where index=* by index, sourcetype and verify EventCode, Logon_Type, src_ip, TargetUserName are populated — null fields silently zero out the brute-force and spray searches.
• CIM mapping gaps: the tstats ... from datamodel=Authentication/Endpoint pivots undercount if Sysmon isn't mapped (process_access EventCode 10 frequently unmapped) or acceleration is stale. Confirm Authentication.action, Endpoint.Processes.process_name resolve before trusting accelerated results.
• Sysmon config coverage: EventCode 10 (LSASS access), 13 (registry), 22 (DNS) only exist if the deployed Sysmon config includes those rules — a SwiftOnSecurity vs Olaf Hartong config difference means token-manipulation and run-key searches return nothing on hosts with a stripped config. Verify event volume per EventCode per host.
• Validate the search fires: generate the behavior in a lab (e.g., 25 4625 failures then a 4624 success, or mimikatz LSASS access) and confirm the saved search alerts before relying on it.
• FP tuning: scope out service accounts and scanners (vuln scanners trigger mass 4625 Logon_Type 3; backup agents trigger SeBackupPrivilege 4672; EDR sensors legitimately open LSASS) via lookup-based allowlists, not by raising count thresholds that hide low-and-slow password spray.