EXTENDED DETECTION AND RESPONSE (XDR)

Secure - One

From SOC Operations to Security Product Engineering

Secure - One is an independently engineered XDR project focused on Windows endpoint telemetry, threat detection, behavioral analysis, threat intelligence, and coordinated security response.

Built from practical experience in enterprise Security Operations Centers, the project explores how endpoint security capabilities can be developed, integrated, and managed through a centralized security architecture.

  • Extended Detection and Response (XDR)
  • Go
  • Windows Endpoint Security
  • Detection Engineering
  • Sigma Rules
  • Behavioral Detection
  • Threat Intelligence
  • Host Firewall
  • Incident Response
  • SOC Engineering
Status: Implemented

Components present and functionally validated.

Status: Under Development

Partial implementation or incomplete integration.

Status: Validation Ongoing

Components requiring additional testing.

Status: Planned

Capabilities designed but not yet implemented.

01Why I Built It

From Operating Security Technologies to Engineering Them

Working in enterprise Security Operations Centers exposed me to the operational challenges of endpoint monitoring, threat detection, incident investigation, and response coordination.

Modern SOC environments generate enormous volumes of security telemetry. Although security technologies provide extensive visibility, analysts frequently encounter fragmented information, repetitive investigations, false positives, and disconnected response workflows.

These challenges motivated me to explore how XDR technologies work at an engineering level.

I wanted to move beyond configuring and operating security products to understanding how their core capabilities could be designed and implemented.

That motivation led to the development of Secure - One.

The project began with a clear objective: engineer a Windows endpoint-focused XDR architecture capable of collecting telemetry, processing security events, detecting suspicious behavior, and supporting investigation and response through a centralized interface.

My primary goals were to:

  • Understand endpoint-agent architecture and communication.
  • Develop reliable security telemetry collection.
  • Build and evaluate detection logic.
  • Explore behavioral detection techniques.
  • Integrate threat intelligence into investigation workflows.
  • Design controlled endpoint response mechanisms.
  • Understand the performance and reliability requirements of endpoint security software.

Secure - One represents the intersection of my SOC experience, detection engineering knowledge, and software development interests.

It is an ongoing engineering project that continues to evolve through implementation, testing, and architectural improvements.

02Architecture

Designing an Agent-Based XDR Architecture

Secure - One follows a modular architecture separating endpoint monitoring, security event processing, detection logic, centralized management, and response operations.

The architecture is designed to support endpoint-level visibility while providing a foundation for centralized management of multiple devices.

A. Windows Endpoint Agent
The endpoint agent is developed primarily in Go.

Its responsibilities include collecting supported endpoint telemetry, processing local security logic, maintaining operational state, and communicating with the management backend.

The agent architecture emphasizes lightweight execution, modular components, and reliable event handling.

B. Telemetry Processing Layer
Collected security events are converted into structured records that can be evaluated consistently.

This layer supports event normalization, processing, and preparation for detection evaluation.

C. Detection Engine
The detection subsystem evaluates relevant events using configurable rules and detection logic.

Sigma-based rule processing forms part of the detection engineering framework.

D. Management Backend
The backend supports endpoint enrollment, authentication, event handling, alert management, and communication with registered devices.
E. XDR Management Console
The web-based console provides centralized visibility into endpoint status, security events, and generated alerts.

It serves as the primary interface for security investigation and endpoint management.

F. Response Architecture
The response subsystem is designed to connect centralized analyst actions with endpoint-side execution.

Complete command delivery, execution, acknowledgement, and verification remain areas of ongoing engineering work.

Architecture Principles

  • Modular component design.
  • Separation of collection, detection, and response.
  • Structured security event processing.
  • Endpoint-specific management.
  • Centralized operational visibility.
  • Controlled administrative access.
  • Performance-conscious agent execution.
  • Extensibility for additional security capabilities.
Event path · Threat intelligence enrichment · Separate response path
  1. 01Windows Endpoint
  2. 02Go Endpoint Agent
  3. 03Telemetry Collection
  4. 04Event Normalization
  5. 05Detection Engine← Threat Intelligence
  6. 06Alert Processing
  7. 07Management Backend
  8. 08XDR Console
Threat Intelligence

Supporting enrichment component feeding detection and investigation context.

Response Orchestration

Separate command path: XDR Console → Management Backend → Go Endpoint Agent. Under development.

Events and response commands travel on separate paths, not one synchronous sequence.

A.Windows Endpoint Agent

Developed primarily in Go. Collects supported endpoint telemetry, processes local security logic, maintains operational state, and communicates with the management backend. Emphasizes lightweight execution, modular components, and reliable event handling.

Status: Validation Ongoing
B.Telemetry Processing Layer

Converts collected security events into structured records that can be evaluated consistently — supporting event normalization, processing, and preparation for detection evaluation.

Status: Validation Ongoing
C.Detection Engine

Evaluates relevant events using configurable rules and detection logic. Sigma-based rule processing forms part of the detection engineering framework.

Status: Validation Ongoing
D.Management Backend

Supports endpoint enrollment, authentication, event handling, alert management, and communication with registered devices.

Status: Validation Ongoing
E.XDR Management Console

Web-based console providing centralized visibility into endpoint status, security events, and generated alerts — the primary interface for investigation and endpoint management.

Status: Validation Ongoing
F.Response Architecture

Connects centralized analyst actions with endpoint-side execution. Complete command delivery, execution, acknowledgement, and verification remain areas of ongoing engineering work.

Status: Under Development
03Telemetry

Building Reliable Endpoint Visibility

Security detection depends on the quality and availability of telemetry.

A major part of Secure - One involved designing the collection and processing of security-relevant endpoint events.

The telemetry architecture focuses on obtaining useful endpoint activity information and converting it into structured records suitable for investigation and detection.

Telemetry Areas
Windows Event Monitoring: Collection and processing of relevant Windows security and system events.

Process Activity: Visibility into supported process execution activity and associated metadata.

File Activity: Monitoring security-relevant file-system operations and suspicious modifications.

Network Activity: Processing supported endpoint network-related events.

Security Alerts: Recording detection results and associated event information.

Agent Health: Monitoring endpoint-agent operational state and connectivity.

Telemetry Processing Workflow

  1. 01Collect supported endpoint events.
  2. 02Extract relevant event attributes.
  3. 03Normalize records into a consistent structure.
  4. 04Process events through applicable detection logic.
  5. 05Generate alerts when detection conditions are satisfied.
  6. 06Make relevant event and alert information available for investigation.

During development, local structured event and alert storage was used to support troubleshooting and validation.

One of the most important design considerations was balancing visibility with resource consumption.

Continuous security monitoring must not unnecessarily degrade endpoint performance.

This required attention to event processing efficiency, memory utilization, CPU consumption, and reliability.

Telemetry processing workflow
  1. Collect events
  2. Extract attributes
  3. Normalize records
  4. Detection logic
  5. Generate alerts
  6. Investigation
04Detection EngineeringStatus: Validation Ongoing

Transforming Endpoint Events into Security Findings

Collecting security events is only the first step in building an effective detection system.

The real challenge is converting raw telemetry into meaningful, explainable, and actionable security findings.

Secure - One incorporates a rule-driven detection architecture with support for Sigma-based detection logic.

Detection Engineering Components
Event Normalization: Converting collected telemetry into consistent event representations.

Rule Evaluation: Matching relevant event attributes against configured detection conditions.

Suspicious Activity Identification: Identifying activity that satisfies security detection criteria.

Alert Generation: Creating structured security alerts containing relevant investigation context.

Detection Maintenance: Supporting modification and expansion of detection logic.

Detection Workflow
Telemetry Collection → Event Normalization → Rule Evaluation → Detection Match → Alert Generation → Analyst Investigation

My experience with enterprise SIEM platforms, MITRE ATT&CK, detection tuning, and SOC investigations influenced the engineering approach.

An important objective was to make detection logic understandable rather than treating every alert as an unexplained result.

The architecture is intended to support continued rule development, testing, and refinement.

Detection coverage and accuracy must be validated against representative datasets and controlled attack simulations before making broader effectiveness claims.

Detection workflow
  1. Telemetry Collection
  2. Event Normalization
  3. Rule Evaluation
  4. Detection Match
  5. Alert Generation
  6. Analyst Investigation
05Behavioral Detection / NGAVStatus: Under Development

Exploring Detection Beyond Static Signatures

Traditional signature-based detection is valuable for identifying known threats, but malicious activity may also be identified through suspicious behavior.

Secure - One includes behavioral detection engineering focused on analyzing endpoint activity and recognizing patterns associated with potentially malicious operations.

Behavioral Detection Areas

  • Suspicious process execution.
  • Unusual process relationships.
  • Potentially malicious command execution.
  • Security-relevant file operations.
  • Sequences of suspicious endpoint activity.
  • Correlation of related detection indicators.

The behavioral detection design emphasizes observable activity rather than depending exclusively on static file signatures.

Engineering Approach

  1. 01Capture relevant endpoint activity.
  2. 02Extract behavioral indicators.
  3. 03Evaluate supported detection conditions.
  4. 04Identify potentially suspicious activity.
  5. 05Generate investigation-ready alerts.
  6. 06Refine detection logic through testing.

NGAV-related logic has been part of the development effort, including work to integrate behavioral detection functionality more directly into the endpoint agent.

However, complete endpoint-agent integration and comprehensive protection validation remain ongoing.

Secure - One should not be described as a certified antivirus replacement or a fully validated NGAV product.

The purpose of this subsystem is to explore behavioral detection engineering and its role within an XDR architecture.

Behavioral indicators feeding detection
  • Suspicious process execution
  • Unusual process relationships
  • Potentially malicious command execution
  • Security-relevant file operations
  • Sequences of suspicious activity
  • Correlated detection indicators
Behavioral detection → investigation-ready alert
06Threat IntelligenceStatus: Validation Ongoing

Enriching Security Events with Threat Context

Threat intelligence can help analysts understand whether observed endpoint activity is associated with known malicious indicators.

Secure - One includes threat intelligence integration work designed to enrich security monitoring and detection workflows.

Core Areas
Indicator Processing: Handling supported indicators of compromise.

Intelligence Feed Integration: Incorporating external intelligence data into the detection architecture.

Event Enrichment: Associating relevant endpoint activity with available intelligence context.

Indicator Matching: Evaluating observed activity against supported threat intelligence indicators.

Investigation Context: Providing additional information to assist analyst decisions.

Engineering Considerations
Threat intelligence introduces challenges involving data quality, freshness, duplicate indicators, false positives, and efficient processing.

A threat intelligence match should be treated as an investigative signal rather than automatic proof of malicious activity.

The architecture is designed to support intelligence-assisted detection while maintaining appropriate validation and analyst review.

Threat intelligence enrichment
  1. Intelligence feeds
  2. Indicator processing
  3. Indicator matching
  4. Event enrichment
  5. Analyst review
07Active ResponseStatus: Under Development

Connecting Detection with Endpoint Action

An effective security workflow should support investigation and, where appropriate, controlled response.

Secure - One includes an active-response architecture designed to connect security alerts with endpoint-level administrative actions.

Response Capabilities Under Development

  • Suspicious process termination.
  • File quarantine workflows.
  • Endpoint containment.
  • Endpoint isolation requests.
  • Response command tracking.
  • Endpoint action acknowledgement.
  • Result verification.

The response architecture distinguishes between requesting an action and successfully executing that action.

Intended Response Lifecycle

  1. 01An analyst identifies suspicious activity.
  2. 02An authorized response action is selected.
  3. 03The backend validates and records the request.
  4. 04The command is delivered to the intended endpoint.
  5. 05The endpoint evaluates and executes the supported action.
  6. 06The endpoint reports the execution result.
  7. 07The console displays the verified outcome.

Some response request mechanisms have been developed, but complete endpoint-side execution and acknowledgement remain under implementation.

In particular, process termination and quarantine must not be presented as fully operational without end-to-end validation.

Security response functionality must prioritize authorization, auditability, safe execution, and clear failure reporting.

Intended response lifecycle
  1. Request
  2. Authorization
  3. Delivery (under development)
  4. Execution (under development)
  5. Acknowledgement (under development)
  6. Verification (under development)

Dashed stages are under development.

08Firewall & IsolationStatus: Under Development

Engineering Endpoint Containment Controls

Network containment is an important incident response capability.

When an endpoint is suspected of compromise, restricting its network communication may help prevent further malicious activity.

Secure - One includes host firewall engineering and an architecture for centralized endpoint containment.

Firewall Engineering Areas

  • Host firewall control integration.
  • Endpoint-specific policy handling.
  • Firewall rule management.
  • Network restriction workflows.
  • Isolation design.
  • Safe restoration of connectivity.
Single-Endpoint Management
The architecture is intended to allow administrators to select a specific registered endpoint and apply supported controls to that device.
Multi-Endpoint Management
The management design also considers controlled administration across multiple endpoints.
Safety Considerations
Firewall changes can unintentionally disrupt business connectivity or disconnect the endpoint from its management infrastructure.

For this reason, containment design must account for management communication, authorization, rollback, and reliable enforcement verification.

Host firewall components have undergone development, but complete centralized enforcement and isolation workflows require further validation.

Do not describe isolation as fully implemented unless verified by the current codebase and test results.

Endpoint-specific containment concept
Console selects a registered endpoint
Host firewall policy applied · management channel preserved
Enforcement verified · safe rollback

Concept only — centralized enforcement and isolation require further validation.

09SOC Capabilities

Designing Around Real Security Operations

My professional experience in Security Operations Centers influenced how Secure - One was designed.

The objective was not simply to display endpoint events but to support the operational activities involved in security monitoring and investigation.

Centralized Endpoint Visibility
A management console provides visibility into registered devices and their reported operational status.
Security Event Monitoring
Structured telemetry enables analysts to review relevant endpoint activity.
Alert Investigation
Detection alerts provide a starting point for investigating potentially suspicious behavior.
Detection Engineering
A configurable detection framework supports the development and refinement of security rules.
Endpoint Administration
The architecture supports centralized device management and is being extended for endpoint-specific and multi-endpoint operations.
Operational Health
Agent connectivity and event processing information help identify monitoring or communication problems.
Access Management
Authentication and role-based access control provide a foundation for restricting sensitive administrative functions.
Response Integration
The response architecture is intended to connect investigation workflows with controlled endpoint actions.
SOC Design Philosophy
The console should prioritize investigation clarity, operational reliability, and useful security context.

A successful security platform must help analysts understand what occurred, why it matters, and which actions are appropriate.

10Engineering Challenges

What Building an Endpoint Security System Actually Involves

Developing Secure - One introduced engineering challenges across endpoint monitoring, system performance, detection processing, security controls, and centralized management.

1. Endpoint Performance
Continuous telemetry collection and detection processing consume system resources.

Agent CPU utilization, memory consumption, and event processing behavior required repeated testing and optimization.

2. Reliable Telemetry Processing
A running endpoint agent does not necessarily mean that all telemetry is being collected, processed, and displayed correctly.

Maintaining accurate event flow and operational state required careful troubleshooting.

3. Endpoint Enrollment and Connectivity
Agent registration, authentication, communication reliability, and connectivity after system restarts introduced additional engineering complexity.
4. Detection Accuracy
Detection logic must balance suspicious activity visibility against false-positive generation.

Broad detection rules can create unnecessary alert volume, while overly restrictive rules may miss relevant behavior.

5. Distributed State Synchronization
Keeping endpoint state, alerts, configuration, and console information synchronized required careful design.
6. Response Command Execution
Implementing a response button is relatively straightforward.

Ensuring that the command reaches the correct endpoint, executes safely, and returns a trustworthy result is substantially more challenging.

7. Firewall Safety
Endpoint isolation must avoid unintended disruption and account for recovery mechanisms.
8. Security of the Management System
Authentication, password management, authorization, and secure communication are essential because the management platform itself provides access to sensitive endpoint controls.
9. Testing Under Realistic Conditions
The project required regression testing, integration checks, resource measurements, and repeated validation.

Some scenarios passed, while others revealed environmental limitations or implementation gaps.

These challenges influenced architectural decisions and helped establish clearer boundaries between implemented features and work still in progress.

11What I Learned

Lessons from Building Security Technology

Secure - One changed how I approach cybersecurity engineering.

Working with enterprise security technologies provided valuable operational knowledge, but building the underlying components introduced a different level of understanding.

Detection Depends on Telemetry Quality
Detection rules cannot compensate for missing, inconsistent, or unreliable telemetry.
Performance Is Part of Security Engineering
An endpoint agent must provide security visibility without becoming an operational burden.
Detection and Response Are Separate Engineering Problems
Identifying suspicious activity and safely executing a response require different architectural considerations.
Security Actions Need Verification
A successful request is not the same as a successfully enforced action.
Reliable Architecture Matters
Modular components, predictable communication, controlled access, and consistent state management contribute to long-term reliability.
Testing Must Go Beyond Functional Demonstrations
Passing a unit test does not automatically establish production readiness.

Endpoint security software requires performance, integration, reliability, and security validation.

SOC Experience Improves Product Design
Understanding how analysts investigate incidents helps identify which telemetry, evidence, and workflows are genuinely useful.
Engineering Requires Continuous Iteration
Some features work as intended during early testing, while others reveal architectural limitations that require redesign.

The most important lesson was understanding the relationship between security operations and security engineering.

Secure - One continues to evolve as a practical exploration of endpoint detection, threat analysis, and response architecture.

It reflects my effort to transform operational cybersecurity experience into hands-on security technology development.

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