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I am Daniel, a freelance penetration tester specializing in Active Directory and internal infrastructure security. I identify and validate attack paths that lead to privilege escalation, lateral movement, and domain compromise, then deliver clear findings and prioritized remediation guidance.

OSCP and HTB CAPE certified, with a Master’s degree in Cybersecurity and a background in aerospace security engineering and distributed-systems research. Based in Portugal, I’m available for freelance assessments and subcontracting engagements worldwide.

Job Experience

> Freelance Internal Penetration Tester @ Independent Security Consultant (January 2026 – Present)
Delivered internal network penetration tests for enterprise environments comprising approximately 200–300 endpoints and 400–500 users. Worldwide, remote engagements.

Key Responsibilities & Achievements:
- Privilege Escalation & Lateral Movement: Identified and validated attack paths from initial internal access to domain administrator privileges.
- Internal Infrastructure Assessment: Assessed network segmentation, trust boundaries, exposed services, insecure protocols, and authentication weaknesses across authorized environments.
- Device Exploitation: Exploited misconfigured printers, switches, and IoT devices to demonstrate unauthorized access and lateral movement.
- Reporting & Remediation: Produced executive summaries and detailed technical reports with validated findings and attack-path evidence, business impact, and prioritized remediation recommendations.
- Stakeholder Debriefing: Delivered remote and onsite technical debriefs to security and infrastructure teams, supporting remediation planning and risk reduction.
> Cybersecurity Engineer @ Osmium Solutions (August 2024 – January 2026)
Secured aerospace and automotive systems through Linux hardening, threat modeling, and offensive assessments within a five-person team supporting EU and ESA-related projects. Remote role across Spain and Italy.

Key Technical Achievements:
- System Hardening: Mitigated boot-level attack paths through kernel hardening and SELinux restrictions.
- Security-Control Coverage: Improved coverage to 80% against ANSSI and 86% against NIST across the assessed core controls.
- Offensive Assessments: Conducted security assessments of aerospace embedded systems, identifying exploitable attack paths.
- Technical Reporting: Documented findings and remediation recommendations for security and engineering stakeholders.
> Cybersecurity Researcher @ Instituto de Telecomunicações (October 2021 – December 2023)
Analyzed decentralized P2P energy-trading platforms and gRPC-based IoT infrastructure for consensus, cryptographic, and network-layer weaknesses. Based in Aveiro, Portugal.

Key Technical Achievements:
- Threat Modeling: Assessed distributed systems to identify critical attack paths, exploitation scenarios, and asynchronous abuse cases.
- Smart Contract Security: Audited smart contracts for transaction-manipulation risks, supporting secure energy and cryptocurrency exchange at 15-minute intervals.
- Open-Source Contributions: Contributed fixes to the Hedera JavaScript SDK, resolving core configuration issues and improving protocol resilience in production code.
- Platform Impact: Supported a Renewable Energy Community platform that reduced monthly energy invoices by up to 63%.