Available for opportunities

David Wairimu Cybersecurity Practitioner | Network Security | Digital Forensics Building verifiable capability through labs, technical documentation, and hands-on practice

I build and document practical cybersecurity projects across network security, Linux security, digital forensics, vulnerability assessment and defensive security. My work is supported by hands-on labs, technical documentation, and verifiable platforms.

Explore My Work Download CV Contact Me
TryHackMe Hack The Box pwn.college Medium
Introduction

Who I am and what I'm building

I am a cybersecurity practitioner who learns by doing. My time is spent in Linux terminals, network simulators, and security labs — configuring, testing, and documenting what I find.

My current focus is security engineering — secure system design, infrastructure security, monitoring, automation, and defensive practices. I document my work publicly, providing verifiable evidence of my technical development.

Focus Areas

What I work with

Cybersecurity

Security fundamentals, threat landscape, defensive strategies

Networking

Cisco Packet Tracer, VLANs, routing, switching

Linux

Command line, system administration, scripting

Ethical Hacking

TryHackMe, Hack The Box, pwn.college labs

Digital Forensics

Evidence acquisition, analysis, reporting

Security Engineering

System hardening, automation, infrastructure security

Featured Work

Featured projects

My actual public repositories, documented as technical case studies.

David-Wairimu-Cybersecurity-Portfolio

GitHub · Public Repository

Overview

A cybersecurity portfolio repository that serves as the central hub for my practical work, lab write-ups, and technical documentation.

Technologies & tools

MarkdownGitGitHubCybersecurity
View on GitHub

Network Security Labs

Cisco Packet Tracer labs covering VLANs, inter-VLAN routing, and basic network security configurations.

CiscoVLANsRouting
GitHub

Cybersecurity Lab Write-ups

Documented walkthroughs and notes from TryHackMe rooms, Hack The Box machines, and pwn.college challenges.

MarkdownLinuxSecurity
GitHub

Security Scripts & Automation

Small utility scripts for file analysis, log parsing, and repetitive security tasks.

PythonBashLinux
GitHub
View All Projects
Practical Learning

Cybersecurity platforms

TryHackMe

netsecwairimu

Completed learning paths, rooms, and hands-on exercises covering network security, Linux, and web fundamentals.

View Profile

Hack The Box

019ec1de-a4cd-70f1-a014-d47638173cfe

Practising on machines and challenges. Developing enumeration, exploitation, and privilege escalation skills.

View Profile

pwn.college

david-netsec1

Working through security challenges and modules. Building foundational skills in binary exploitation and system security.

View Profile
Writing

Technical writing

Technical articles on Medium

Cybersecurity · Networking · Tutorials
Read My Technical Writing

Let's Connect

Open to cybersecurity opportunities, technical collaborations, internships, junior security roles, security operations opportunities and relevant technology projects.

Email Call GitHub
Who I Am

Profile

A brief introduction — who I am, what I do, and where I'm heading.

David Wairimu — Cybersecurity Practitioner

David Wairimu

Cybersecurity Practitioner / Security Engineering

I'm a cybersecurity practitioner based in Kenya. I learn by building — configuring networks in Cisco Packet Tracer, solving rooms on TryHackMe, breaking machines on Hack The Box, and working through security challenges on pwn.college. Every lab, script, and misconfiguration I encounter gets documented because evidence matters more than claims.

My work sits at the intersection of networking, Linux, and security. I'm currently moving towards security engineering — the discipline of designing, hardening, monitoring, and automating secure systems. I share what I learn on Medium and publish all my lab work and code on GitHub.

Based in Kenya
Focus Cybersecurity → Security Engineering
Labs TryHackMe · Hack The Box · pwn.college
Languages Python · Bash · JavaScript · Node.js · C++ · SQL · HTML · CSS · JSON · Markdown · Git · Linux Shell
Tools & Platforms Wireshark · Nessus · Palo Alto · Hexnode UEM · Linux · Cisco Packet Tracer · GNS3 · TryHackMe · Hack The Box · pwn.college
GitHub TryHackMe Hack The Box pwn.college Medium Email
01 — About

My approach

I focus on building real, verifiable skills through practical work and documentation.

I am a cybersecurity practitioner who learns by doing. My time is spent in Linux terminals, network simulators, and security labs — configuring, testing, and documenting what I find.

My background spans networking fundamentals (Cisco Packet Tracer, VLANs, routing/switching), hands-on cybersecurity platforms (TryHackMe, Hack The Box, pwn.college), and enterprise security tooling including Palo Alto firewalls and Hexnode UEM. I apply these through practical security work covering vulnerability assessment, digital forensics, endpoint management, and defensive security.

I am currently venturing into security engineering — studying how secure systems are designed, configured, monitored, and hardened. I document my journey publicly because evidence matters more than claims.

Currently

Building hands-on cybersecurity labs
Practising on TryHackMe & Hack The Box
Solving pwn.college challenges
Working with Palo Alto firewalls & Hexnode UEM
Studying security engineering concepts
Documenting everything on GitHub & Medium
Open to cybersecurity opportunities
02 — Skills

Technical skills

Technologies and skills developed through actual projects, labs, and documented learning.

Cybersecurity

Hands-on security practice across platforms

Network Security Ethical Hacking Vulnerability Assessment Incident Response Digital Forensics Defensive Security

Networking

Cisco Packet Tracer, routing, switching, network design

Cisco Networking Routing & Switching VLANs DHCP WLAN STP EtherChannel HSRP

Security Tools & Platforms

Tools and platforms used in practical labs

Python Bash JavaScript Node.js SQL Wireshark Nessus Palo Alto Firewalls Hexnode UEM Linux Git GitHub Cisco Packet Tracer GNS3 TryHackMe Hack The Box pwn.college

Languages & Scripting

Languages and formats used to build tools, scripts, and documentation

Python Bash JavaScript Node.js SQL C++ JSON HTML CSS Markdown Git Linux Shell
Technical Evidence

Evidence Behind the Skills

Each area below is backed by actual labs, tools, or documented work. Links lead to public evidence where it exists.

Networking

Network Design & Configuration

Cisco Packet Tracer · GNS3

VLANs · Trunking · Inter-VLAN Routing · STP · EtherChannel · HSRP · DHCP · WLAN

View Evidence →
Security

Security Tooling & Practice

Wireshark · Nessus · Palo Alto · Linux

Traffic analysis · Vulnerability assessment · Firewall configuration · Linux security hardening

View Evidence →
Digital Forensics

Investigation & Analysis

Forensic methodology & reporting

Evidence handling · Investigation · Analysis · Technical reporting

View Evidence →
03 — Projects

Featured Projects

Practical security work, labs, and technical documentation. All links lead to real public resources.

USB Monitoring & Intrusion Detection

Python · Linux · Security Automation

Overview

A security monitoring project designed to detect and log USB device activity, providing visibility into removable-device events on Linux systems.

Security Concepts

Endpoint monitoring, event logging, removable media control, and defensive visibility.

Technologies

PythonLinuxudevSecurity Monitoring
View Project →

Cisco Network Security Lab

Cisco Packet Tracer · Networking · VLANs

Overview

Practical network security and infrastructure labs covering VLANs, trunking, inter-VLAN routing, STP, EtherChannel, DHCP, WLAN and Layer 2 security concepts.

Technologies

Cisco Packet TracerVLANsRouting & SwitchingSTPEtherChannel
View Project →

Cybersecurity Lab Write-ups

TryHackMe · Hack The Box · pwn.college

Overview

Documented practical security exercises covering enumeration, Linux security, web security, privilege escalation and defensive security concepts.

Platforms

TryHackMeHack The Boxpwn.collegeLinux
TryHackMe → Hack The Box → pwn.college →
GitHub Evidence

Repositories & Public Work

Public repositories documenting cybersecurity, networking, and security automation work.

View GitHub Profile

David-Wairimu-Cybersecurity-Portfolio

The central hub for practical work, lab write-ups, and technical documentation across cybersecurity and networking.

MarkdownGitCybersecurity
View Repository →

Additional Repositories

Networking labs, security scripts, and documentation are published as they are completed.

PythonBashNetworking
Browse All →

* Only real, published repositories are shown. Additional work is added to GitHub as it is completed.

04 — Labs

Where I practise

Hands-on platforms where I build practical cybersecurity skills. All profiles are real and verifiable.

TryHackMe

netsecwairimu

Completed learning paths, rooms, and hands-on exercises covering network security, Linux, and web fundamentals.

View TryHackMe Profile

Hack The Box

019ec1de-a4cd-70f1-a014-d47638173cfe

Practising on machines and challenges. Developing enumeration, exploitation, and privilege escalation skills.

View Hack The Box Profile

pwn.college

david-netsec1

Working through security challenges and modules. Building foundational skills in binary exploitation and system security.

View pwn.college Profile

* Platform statistics and achievements are displayed on the respective profiles. I do not fabricate numbers here.

05 — Direction

Venturing into Security Engineering

My cybersecurity practice is increasingly moving towards understanding how secure systems are built and maintained.

I am intentionally developing my skills toward security engineering — the discipline of designing, configuring, monitoring, hardening, testing, automating, investigating, and maintaining secure systems.

This direction builds on my existing work in networking, Linux, cybersecurity labs, automation, infrastructure, vulnerability assessment, and defensive security.

System design
Secure configuration
Monitoring
Hardening
Testing
Automation
Investigation
Maintenance

* Current Development Focus: secure system design, infrastructure security, security hardening, monitoring, automation, and security engineering practices.

06 — Certifications

Training & certifications

Professional certifications I have earned across cybersecurity, networking, and IT infrastructure.

Completed

Cybersecurity Program

Mediacrest Training College

Digital Forensics, Network Security, Threat Detection, Security Compliance, Incident Management.

Completed

Network Security Fundamentals

Palo Alto Networks

Certificate ID: C427489 · Issued October 2024.

Completed

Cybersecurity Fundamentals

Palo Alto Networks

Certificate ID: C427485 · Issued October 2024.

Completed

CCNA: Introduction to Networks

Cisco Networking Academy · ZETECH UNIVERSITY

Foundations of networking, routing, switching, and IP addressing.

Completed

Ethical Hacker

Cisco Networking Academy

Methodological ethical hacking, penetration testing, vulnerability scanning, and reporting.

Completed

Hexnode Certified MSP Mastery

Hexnode

Certificate No: 167738938 · Valid Nov 2025 – Nov 2027. Unified Endpoint Management.

Completed

TXOne Certified Solutions Associate

TXOne Networks

OT threat landscape, OT zero trust, and TXOne solutions foundation. Valid 2025 – 2028.

Completed

Apply AI: Analyze Customer Reviews

Cisco Networking Academy · ZETECH UNIVERSITY

Applied AI for text analysis and customer review processing.

Completed

Networking Academy Learn-A-Thon 2026

Cisco Networking Academy

Award in recognition of exceptional learning achievement.

* Certificates are available upon request.

07 — Education

Education

Academic qualifications and professional credentials.

Details

Education details are available upon request.

Full academic qualifications, institution names, and dates will be provided upon request.

08 — Achievements

Genuine evidence

Real achievements from hands-on work and learning.

Achievement

TryHackMe Pre-Security Path

Completed all foundational modules
Achievement

Cisco Packet Tracer Labs

Designed and configured multi-VLAN network topologies
Achievement

pwn.college Progress

Solved introductory security challenges
Achievement

Hack The Box Machines

Completed beginner-friendly machines
Achievement

Technical Documentation

Maintained public GitHub repos with lab write-ups
Achievement

Medium Articles

Published technical posts on cybersecurity topics
09 — Experience

Professional Experience

Technology, business, and IT-related experience.

Lorraine Electronics Enterprise

Computer hardware, laptop and desktop support, troubleshooting, IT equipment, client technical support, and technology solutions.

* Technology and IT support experience. Not a cybersecurity-specific role.

10 — Writing

Technical writing

I write about cybersecurity, networking, and technology on Medium.

Technical articles on Medium

Cybersecurity · Networking · Tutorials
Read My Technical Writing

* Article titles and descriptions are displayed on Medium. I do not fabricate articles or publication dates.

11 — Contact

Let's Work Together

Open to cybersecurity opportunities, technical collaborations, internships, junior security roles, security operations opportunities and relevant technology projects.

David Wairimu

Cybersecurity Practitioner / Security Engineering

+254 794 066 681
david.wairimu@proton.me
Email Call WhatsApp GitHub

Send me a message

You can also email me directly at david.wairimu@proton.me.