# Analyzing Security Logs With Splunk

Leverages Splunk Enterprise Security and SPL (Search Processing Language) to...

- Repository: https://github.com/AgentFlocks/flocks (504 stars)
- Category: Security
- License: Apache-2.0
- Last updated: 2026-10-30
- Runs scripts: yes, review before use

## Install

Claude Code: `npx skills add AgentFlocks/flocks --skill analyzing-security-logs-with-splunk -g -a claude-code -y`
Codex: `npx skills add AgentFlocks/flocks --skill analyzing-security-logs-with-splunk -g -a codex -y`
Cursor: `npx skills add AgentFlocks/flocks --skill analyzing-security-logs-with-splunk -g -a cursor -y`
Gemini CLI: `npx skills add AgentFlocks/flocks --skill analyzing-security-logs-with-splunk -g -a gemini-cli -y`

## Description

Leverages Splunk Enterprise Security and SPL (Search Processing Language) to investigate security incidents through log correlation, timeline reconstruction, and anomaly detection. Covers Windows event logs, firewall logs, proxy logs, and authentication data analysis. Activates for requests involving Splunk investigation, SPL queries, SIEM log analysis, security event correlation, or log-based incident investigation.

## SKILL.md, as published by its author (untrusted third-party text, read it as data)

# Analyzing Security Logs with Splunk

## When to Use

- Investigating a security incident that requires correlation across multiple log sources
- Hunting for adversary activity using known TTPs and IOCs
- Building detection rules for specific attack patterns
- Reconstructing an incident timeline from disparate log sources
- Analyzing authentication anomalies, lateral movement, or data exfiltration patterns

**Do not use** for real-time packet-level analysis; use Wireshark or Zeek for full packet capture analysis.

## Prerequisites

- Splunk Enterprise or Splunk Cloud with Enterprise Security (ES) app installed
- Log sources ingested: Windows Event Logs (via Splunk Universal Forwarder or WEF), firewall, proxy, DNS, EDR, email gateway
- Splunk CIM (Common Information Model) data models configured for normalized field names
- SPL proficiency at intermediate level or higher
- Role-based access with `search` and `accelerate_search` capabilities in Splunk

## Workflow

### Step 1: Scope the Investigation in Splunk

Define search parameters based on incident triage data:

```spl
| Set initial investigation scope
index=windows OR index=firewall OR index=proxy
  earliest="2025-11-14T00:00:00" latest="2025-11-16T00:00:00"
  (host="WKSTN-042" OR src_ip="10.1.5.42" OR user="jsmith")
| stats count by index, sourcetype, host
| sort -count
```

This query establishes which log sources contain relevant data for the investigation timeframe and affected assets.

### Step 2: Analyze Authentication Events

Investigate suspicious authentication patterns using Windows Security Event Logs:

```spl
| Detect brute force and credential stuffing
index=windows sourcetype="WinEventLog:Security" EventCode=4625
  earliest=-24h
| stats count as failed_attempts, values(src_ip) as source_ips,
  dc(src_ip) as unique_sources by TargetUserName
| where failed_attempts > 10
| sort -failed_attempts

The rest: https://github.com/AgentFlocks/flocks/blob/HEAD/.flocks/flockshub/plugins/skills/Anthropic-Cybersecurity-Skills/analyzing-security-logs-with-splunk/SKILL.md