Build Your Own SIEM: Why These Open-Source Tools Just Work

Most of my content is pretty technical — walkthroughs, configs, detections, integrations. But this post is different. It’s less about how and more about why.

If you’re thinking about building a SIEM stack from open-source tools, you’re probably wondering the same thing I did years ago:

“Can I actually pull this off without a six-figure budget… and will it actually work?”

The answer: yes — if you choose the right tools, in the right way.

This post breaks down the open-source stack we use at SOCFortress and why each tool earned its place. It’s built from real-world lessons, lots of tinkering, and a ton of late nights.

? The Problem With Traditional SIEMs

Let’s be honest. Most commercial SIEM/SOAR platforms are:

• ? Expensive — High five- to six-figure licensing models
• ? Closed — You’re locked into their ecosystem
• ? Fragmented — Tools don’t talk to each other
• ? Manual — Automation is gated behind enterprise tiers
• ? Limited — Integrations are slow and vendor-driven

Sound familiar?

I knew we could do better — with open-source. But I didn’t just want to spin up random tools. I needed a cohesive, modular, scalable, and defender-friendly stack.

? The Stack That Just Works

Here’s what we landed on:

1. Wazuh – Endpoint Visibility & Detection

Wazuh is where it all starts. It collects logs from endpoints and monitors file changes, user activity, processes, and more. It’s our detection backbone.

Why we use it:

• Agent-based monitoring across OSes
• Built-in rules and syscheck
• Lightweight and scalable

Its limitations:

• Not ideal for firewall logs
• Weak on log normalization

2. Graylog – Log Ingestion & Enrichment

Graylog became our log brain. It ingests everything Wazuh can’t — firewalls, routers, syslog forwarders — and lets us normalize, enrich, and route logs.

Why we use it:

• Real-time enrichment (VirusTotal, GeoIP, custom APIs)
• Multi-tenant & scalable
• Great log search and pipeline rules

Its limitations:

• Not a detection engine
• Needs something like Wazuh to complement it

3. Grafana – Dashboards That Make Sense

All that data needs to be visible. Grafana gives us fully customized dashboards for alert trends, SOC KPIs, vulnerability summaries, and more.

Why we use it:

• Integrates with Wazuh Indexer (OpenSearch), MySQL, APIs
• Beautiful, customizable dashboards
• Loved by both analysts and clients

4. Velociraptor – Scalable DFIR

When we need to dig deeper, Velociraptor is our go-to. It’s an incident response powerhouse.

Why we use it:

• Remote memory, registry, file, and artifact collection
• Query endpoints in real-time
• Doesn’t interrupt end users

Bonus: Our endpoints run both the Wazuh and Velociraptor agents — detection + IR on tap.

5. Shuffle – SOAR Automation

Shuffle is the glue. It automates workflows between all our tools and external systems like Jira, VirusTotal, and email gateways.

Why we use it:

• Drag-and-drop playbooks
• Connects our stack to the outside world via APIs
• Makes our SOC proactive, not reactive

6. CoPilot – Unified Interface for Analysts

Finally, we built CoPilot — our own open-source platform to tie it all together.

What it does:

• Alert triage & case management
• Launch Velociraptor scans
• Trigger Shuffle playbooks
• Multi-tenant SOC view
• Custom health checks and reporting

Think of it like the cockpit for your SOC.

? How It All Connects

Every piece in this stack solves a specific problem. But the magic is in how they work together:

• Endpoints → Wazuh for monitoring
• Firewalls/3rd parties → Graylog for parsing
• Graylog → Wazuh Indexer for storage
• Grafana → Wazuh Indexer for dashboards
• Velociraptor connects for DFIR
• Shuffle automates everything
• CoPilot gives your team one interface to run the show

Modular. API-driven. Scalable. Open-source.

No vendor lock-in. No bloat.

? Want to See the Diagram?

Here’s the full network diagram we use in the video → https://app.eraser.io/workspace/0zwk56XTz2g5Ytk6fbwV?origin=share

? Final Thoughts

This stack was built out of necessity. We didn’t have a huge budget. We had real problems, a growing team, and a mission to deliver world-class detection and response without locking ourselves into a black box.

So we made something better — and we made it ours.

If you’re ready to ditch bloated platforms and build something that works for your team, you’re in the right place.

Let’s connect:

? [email protected]

? YouTube.com/@taylorwalton_socfortress

Need Help?

The functionality discussed in this post, and so much more, are available via the SOCFortress platform. Let SOCFortress help you and your team keep your infrastructure secure.

Website: https://www.socfortress.co/

Contact Us: https://www.socfortress.co/contact_form.html