Author: Haji Aderrahman
Project Status: π§ Active Development
Welcome to the Elastic Stack SIEM Complete Guide. This project is designed to be more than just a tutorialβit is a comprehensive journey into the world of Security Operations.
To get the most out of this guide, I recommend following the modules in order:
- Module 1: Master the fundamentals of SIEM (Security Information and Event Management).
- Module 2: Understand the market landscape and why we chose the Elastic Stack.
- Module 3: Deep dive into the Elastic Stack architecture (ELK) and modern ingestion strategies.
- Module 4: Hands-On Labs β Step-by-step deployment guides for various architectures.
π‘ Tip: This repository is designed to complement the Official Elastic Documentation. Use this guide for practical, real-world context and the official docs for API references or for get more deep on each informatioin.
π§
β οΈ Note : this is a work of days and night, so itβs will be a nice step from you to support me however you want repost it sugges my profil on opporurnitys or taking a caffe for me.
π Table of Contents (Click to Expand)
- Readme
- π The Complete Elastic Stack SIEM Guide
- Module 1: What is a SIEM ? π‘οΈ
- 1. The Story of SIEM
- 2. Definition: What exactly is a SIEM? π§
- Beyond Simple Logging
- The "SIEM Formula"
- 3. Types of Data: Logs, Metrics, and Events π
- A. Logs (The "What Happened" Record) π
- B. Metrics (The "How is it Running" Measurement) π
- C. Events (The "Important Occurrence") π
- 4. SIEM Workflow: The Journey of a Log π
- Stage 1: Multi-Source Collection π₯
- Stage 2: Aggregation and Normalization π§©
- Stage 3: Log Parsing and Enrichment π
- Stage 4: Correlation and Threat Detection π§
- Stage 5: Alert Generation and Prioritization π¨
- Stage 6: Automated Response and Containment (SOAR) π€
- Stage 7: Incident Resolution and Reporting π
- Stage 8: Continuous Monitoring and Improvement π
- 5. SIEM Architecture: The Engine Under the Hood ποΈ
- Module 2 : Why ELK ? π
- Module 3 : What is Elastic Stack
- 1. The Story: "You Know, for Search." π°οΈ
- 2. The Core Components (The "Engine") βοΈ
- 4. Modern Data Ingestion: Elastic Agent & Fleet β
- A. The Elastic Agent (The Unified Soldier) π‘οΈ
- B. Fleet Server (The Command Center) π°
- 5. Data Ingestion Strategies: How We Handle Different Sources π§¬
- A. Systems Supporting Elastic Agents (The Direct Method) π»
- B. Systems with Pre-built Integrations (The Syslog/IP Trick) π
- C. Legacy & Closed Solutions (The Logstash Power-User Method) π οΈ
- Module 4 : π«πHands on labππ«
But first, before diving into the theoretical and detailed technical explanation of SIEM, letβs see a demo of what we are going to build.
Dive into the world of Security Information and Event Management (SIEM) like a cyber detective in a high-stakes thriller! π΅οΈββοΈ
SIEM did not appear overnight; it evolved from the convergence of two distinct security domains:
- SIM (Security Information Management): Focuses on long-term storage, log collection, and compliance reporting. Think of it as the "Library" π of your infrastructure.
- SEM (Security Event Management): Focuses on real-time monitoring, incident correlation, and immediate response. Think of it as the "Alarm System." π¨.
In 2005, Gartner analysts Mark Nicolett and Amrit Williams coined the term "SIEM." By merging these two concepts, they created the superhero of cybersecurity: a unified platform that collects, analyzes, and responds to threats across your entire network. It's like having a 24/7 digital watchdog π that barks at the slightest anomaly!
At its core, SIEM (Security Information and Event Management) is a centralized security solution that provides a "single pane of glass" for an organization's security posture.
Instead of checking dozens of different security tools, a SIEM aggregates everything into one interface. It works by collecting, normalizing, and analyzing data from across the entire infrastructureβincluding servers, firewalls, endpoints, and cloud services.
A SIEM does more than just store logs; it acts as the "brain" of the SOC (Security Operations Center). It uses Correlation Rules and Anomaly Detection to identify threats that would remain invisible if you looked at each system individually.
The true power of a SIEM lies in this simple equation:
SIM (Long-term storage & Compliance) + SEM (Real-time monitoring & Alerting) = SIEM
By centralizing this "huge data" into a single platform, the SIEM allows security teams to detect, investigate, and respond to incidents faster than ever before.
In the world of the Elastic Stack and SIEM, we deal with three primary types of telemetry. Understanding the difference between them is crucial for effective Detection Engineering. Think of these as the "fuel" that powers your security monitoring.
A log is a timestamped record (text or structured JSON) generated by a system or application. It provides the raw, detailed history of every action taken.
- Characteristics: High granularity, can be structured (ECS) or unstructured.
- Security Use Case: Forensic Investigation. If a breach occurs, logs tell you exactly which command was executed or which sensitive file was modified.
- Example:
2025-10-21 14:02:01 - User 'admin' changed password for 'guest_user' from IP 192.168.1.50
Metrics are numerical measurements of a system's state over time. They are lightweight, efficient, and highly predictable.
- Characteristics: Quantitative (numbers, percentages, gauges).
- Security Use Case: Anomaly Detection. Identifying a DDoS attack (sudden spike in network traffic) or Cryptomining (unexplained 100% CPU usage).
- Example:
CPU Usage: 98%,Network Out: 500MB/s,Disk Space: 10% remaining.
An event is a specific, discrete action that occurred on a system. While every event is recorded as a log, not every log is a significant security event. In a SIEM context, an event is a "Log with actionable meaning."
-
Characteristics: Action-oriented and often triggers a correlation rule.
-
Security Use Case: Real-time Alerting. Identifying critical milestones in an attack kill chain.
-
Example:
Successful Login,Firewall Connection Blocked,New Process Started.
-
Summary
| Data Type | Primary Question | Format | Data Size | Best for... |
|---|---|---|---|---|
| Logs | "Who did what?" | Text / JSON | Heavy | Forensics & Troubleshooting |
| Metrics | "Is the system okay?" | Numbers | Light | Anomaly Detection & Baselining |
| Events | "What just happened?" | Structured | Medium | Real-time Alerting |
To understand how a SIEM transforms millions of raw data points into a single critical alert, we can break down its operation into 8 key stages, based on the standard SOC (Security Operations Center) architecture:
The SIEM begins by gathering logs from every corner of the infrastructure:
- Endpoints: Workstations and servers (Windows, Linux).
- Network: Firewalls (FortiGate), Switches, and Routers.
- Cloud Services: Azure, AWS, Google Cloud.
- Security Tools: IDS/IPS, Antivirus, and EDRs.
Since every device speaks its own "language" (Syslog, JSON, XML, etc.), the SIEM centralizes all data into an aggregation database and converts it into a common format.
π‘ In the Elastic Stack: This is where the Elastic Common Schema (ECS) comes in, ensuring that fields like Source_IP and src_ip are unified into a single searchable field.
The SIEM "parses" the logs to extract essential fields (IP addresses, timestamps, user IDs). It also enriches the dataβfor example, by adding Geo-IP location or checking if an IP is flagged by Threat Intelligence feeds.
This is the "Brain" of the system. The SIEM applies Correlation Rules to link isolated events together.
- Example: 10 Failed Logins (Event A) + 1 Successful Login (Event B) from an unusual IP = Brute Force Alert.
When a rule is triggered, an alert is generated. The SIEM assigns a Severity Score (Low, Medium, High, Critical) so analysts know which threats to investigate first.
Modern SIEMs can trigger immediate "Playbooks" to contain threats without human intervention:
- Blocking a malicious IP on the Firewall.
- Quarantining an infected workstation.
- Disabling a compromised user account.
Once the incident is handled, the SIEM generates detailed reports. This is vital for Compliance and for maintaining a legal audit trail of the attack and the response taken.
Finally, the workflow is a loop. Analysts use "Lessons Learned" from past incidents to fine-tune correlation rules and improve the overall security posture.
As shown in the architecture diagram above, a SIEM acts as a sophisticated funnel, taking raw, chaotic data from the bottom and refining it into clear, prioritized security actions at the top.
As shown in the architecture diagram above, a SIEM acts as a sophisticated funnel, taking raw, chaotic data from the bottom and refining it into clear, prioritized security actions at the top.
A SIEM is not just a single application; it is a complex, multi-layered ecosystem designed to handle massive data flows while providing real-time intelligence. By breaking down the architecture, we can identify the essential components that turn raw logs into actionable security insights.
This is the foundation where data enters the system from the entire infrastructure.
- Event Sources: The SIEM pulls data from a vast array of sources, including Network devices, IPS, Access Control, Applications, Honeypots, and Identity Management (IAM).
- Data Collection Agents: These are the frontline "sensors" (like Elastic Agent or Beats) that capture system events in real-time. Devices that cannot host agents, like your FortiGate firewall, send data via Syslog.
- De-duplication & Normalization: To save storage, Protocol and Application Agents remove duplicate logs and "translate" them into a uniform format (Normalization). In Elastic, this ensures all data follows the Elastic Common Schema (ECS).
Once data is normalized, it moves to the processing core where it is transformed into intelligence.
- The Indexing Database (Event DB): This is the heart of the SIEM where all normalized messages, statistics, and alerts are stored. Modern SIEMs like Elasticsearch allow for near-instant searching across terabytes of data.
- Correlation Engine: This component compares incoming logs against a Knowledge Base of vulnerabilities and security policies to find attack patterns.
- Detection Engine: It runs Correlation Rules (e.g., "5 failed logins + 1 success") to identify threats that would be invisible if looking at systems individually. It may also use Machine Learning to detect anomalies like unusual login times.
This is the top layer where the Security Operations Center (SOC) analysts interact with the system.
- Real-Time Dashboards: Visual representations (Pie charts, maps, timelines) that provide a "Single Pane of Glass" view of the organization's security posture.
- Alert Generation & Prioritization: When a threat is detected, the SIEM generates an alert, prioritizing it by severity so analysts know what to investigate first.
- Incident Response & SOAR: The interface integrates with Ticket Systems and Knowledge Bases to help teams respond. Modern systems can use Automated Playbooks to block malicious IPs or quarantine devices instantly.
This module explores the competitive landscape of SIEM solutions and explains why the Elastic Stack (ELK) is a game-changer for modern Security Operations.
When choosing a SIEM, organizations typically look at the Gartner Magic Quadrant for SIEM. As of 2025/2026, the market is led by a few heavyweights. Below is a comparison of the top contenders:
| Feature | Splunk Enterprise Security | IBM QRadar | Elastic Security (ELK) |
|---|---|---|---|
| Model | Proprietary / Closed Source | Proprietary / Appliance-based | Open Ecosystem / Flexible |
| Pricing | Ingest-based (Can be very expensive) | EPS (Events Per Second) based | Resource-based (Pay for infra) |
| Scalability | High, but costs scale with data | High, but requires complex tuning | Near-Infinite (Horizontal scaling) |
| Deployment | Cloud / On-Prem | Hybrid / Managed | Anywhere (Cloud, Docker, Bare Metal) |
| Learning Curve | Steep (Requires SPL knowledge) | High (Complex Administration) | Moderate (Intuitive Kibana UI) |
| Best For | Massive heterogeneous estates | Highly regulated industries | Modern SOCs & Cost-conscious teams |
- Splunk is the "Swiss Army Knife" but often comes with a "Splunk Tax"βit gets exponentially more expensive as your logs grow.
- QRadar is a powerful legacy beast, perfect for IBM-first environments, but it can feel rigid and "old school" in its interface.
- ELK disrupts this by offering a Search-First approach to security.
After benchmarking, the decision to go with the Elastic Stack is based on four strategic pillars:
Unlike traditional SIEMs that charge you per gigabyte of data you ingest, Elasticβs core is free. You are only limited by the hardware you provide. This allows a company to collect all logs (even low-priority ones) without breaking the budget.
Elasticsearch was born as a search engine. In a security crisis, every second counts. Finding a specific malicious IP among billions of rows is faster in Elastic than in almost any other platform.
This is ELK's "Secret Sauce." It is the only platform where your Logs, Metrics, and Traces live in the same place.
- Example: If a server has 100% CPU usage (Metric), you can immediately see the security logs (SIEM) on the same screen to see if itβs a Cryptomining attack.
Elastic publishes its Detection Rules openly on GitHub. You aren't trapped in a "Black Box." You can modify, improve, and share rules with a global community of security engineers.
Final Verdict: I chose the Elastic Stack for this project because it provides the flexibility of an open-source tool with the power of an enterprise-grade SIEM. It is the most future-proof solution for a modern, data-driven SOC.
The Elastic Stack (formerly known as the ELK Stack) is a collection of open-source products designed to take data from any source, in any format, and search, analyze, and visualize it in real time.
The journey began in 2004 when Shay Banon (the creator of Elasticsearch) was looking for a way to build a search engine for his wifeβs recipe collection. He released Elasticsearch in 2010 with the iconic tagline: "You know, for search."
In 2012, Shay co-founded Elastic alongside Steven Schuurman, Uri Boness, and Simon Willnauer. What started as a simple search engine quickly evolved into the ELK Stack when Elasticsearch joined forces with Logstash (for data processing) and Kibana (for visualization). By 2015, with the addition of Beats, it officially became the Elastic Stack.
The Elastic Stack is composed of four main pillars that work in a seamless pipeline:
| Component | Role | Description | |
|---|---|---|---|
| Elasticsearch π | Storage & Analytics | A distributed, JSON-based search engine. It is the "brain" where your data is indexed and stored. | |
| Logstash π οΈ | Processing Pipeline | A server-side data processing engine that ingests data from multiple sources, transforms it, and sends it to your "brain" (Elasticsearch). | |
| Kibana π¨ | Visualization UI | The window into the stack. It allows you to explore your data, build dashboards, and manage your security alerts. | |
| Beats / Agent π¦ | Data Shippers | Lightweight "messengers" installed on your servers or firewalls to ship logs and metrics directly to the stack. | |
logstash pipline (the output in our case will be elastisearch )
While Beats are still widely used for single-purpose data shipping, most modern Elastic Stack users have shifted to the Fleet ecosystem for a more streamlined and centralized experience.
Instead of installing multiple Beats (Filebeat for logs, Metricbeat for metrics, etc.), you install a single Elastic Agent on your hosts (Windows, Linux, macOS).
- One Agent to Rule Them All: It is a single, unified binary that handles logs, metrics, and security data simultaneously.
- Integrations-Based: It uses pre-built "Integrations" that can be enabled with a few clicks in the UI, eliminating the need to manually edit YAML configuration files.
Managing hundreds of individual agents manually is impossible in a large infrastructure. This is where the Fleet Server comes in as the centralized management hub.
- Centralized Management: From a single "pane of glass" in Kibana, you can view the health and status of every agent across your entire network.
- Remote Policy Updates: When you want to collect a new type of log (like adding FortiGate logs), you simply update the Agent Policy in the Fleet UI. Fleet Server automatically pushes these changes to all enrolled agents instantly.
- Massive Scalability: A single Fleet Server can coordinate thousands of agents, making it the preferred choice for enterprise-level SIEM deployments.
Not all systems in an infrastructure are created equal. As shown in the diagram below, we categorize data sources into three distinct types to determine the most efficient ingestion method.
This is the most straightforward approach. For modern operating systems, we install the Elastic Agent directly on the source.
- How it works: Once installed, the agent automatically establishes a secure connection to the stack and begins shipping data based on its assigned policy.
- Examples: Windows Server, Linux (Ubuntu, CentOS, Debian), and macOS.
- Lab Preview: We will demonstrate how to enroll these agents and manage them remotely from the Fleet UI.
Some devices, like network appliances, are "closed" and do not allow the installation of third-party agents. However, Elastic provides Integrations to handle them.
- How it works: We configure the source system to forward its logs (usually via Syslog) to a specific IP address and port.
- Best Practice: We use the machine hosting the Fleet Server as the listener. By enabling the specific integration in Kibana, the Fleet Server is programmed to listen on a dedicated port, automatically normalizing the incoming logs.
- Examples: FortiGate Firewalls, Cisco Switches, and F5 Load Balancers.
For proprietary or "unknown" systems where no pre-built integration exists, we rely on Logstash.
- How it works: We use Logstash as a middleman. We write custom YAML configuration files (Input, Filter, Output) to manually parse and decode the specific format of the received logs.
- When to use: Use this for closed solutions like Tripwire or Wallix, or custom in-house applications where the log format is unique and not recognized by the global community.
In this section, you will find comprehensive, step-by-step guides to practicing with the Elastic Stack across different architectures. This project currently features two primary versions:
- Standard Version: A single-node deployment for testing and development.
- Cluster Version (Coming Soon): A high-availability production-ready deployment.
- PNETLab Version (Coming Soon): A specialized cluster deployment simulated within PNETLab for network security enthusiasts.
Each guide is frequently updated with new data sources and advanced integrations. For deep dives into specific features, I have also included links to the official Elastic documentation.








