Résumé · James A. Hasewinkle

Summary

Senior Offensive Security Consultant with 5+ years of experience conducting internal/external, web, mobile, cloud, and physical penetration tests across enterprise, industrial, retail, and commercial environments. Specializes in adversary emulation, social engineering, mobile testing, and covert physical intrusion. Skilled in Windows, Linux, Active Directory, AWS/Azure, and full-stack exploitation. Known for clear technical writing, client communication, and delivering high-impact red team engagements from planning to executive reporting.

Experience

Senior Penetration Tester — Zyston LLC

Dallas, TX — Dec 2020 – Nov 2025

Led and executed 100+ offensive security engagements including internal/external infrastructure tests, cloud assessments, web/mobile testing, and full red-team operations.
Performed high-impact physical penetration tests (badge cloning, lock bypass, tailgating, covert camera access, alarm evasion) for industrial, retail, and corporate environments.
Built internal frameworks for external attack surface mapping, phishing infrastructure, and repeatable red team tradecraft.
Conducted complex Active Directory attacks including Kerberoasting, AS-REP Roasting, constrained delegation abuse, and lateral movement using Cobalt Strike, Sliver, and Impacket tooling.
Delivered spear-phishing and multi-stage social engineering campaigns achieving high credential-capture rates and BEC/BPC-style business process compromise evaluations.
Identified critical vulnerabilities including RCE, authentication bypass, broken access control, SSRF, SQLi, deserialization flaws, cloud IAM escalation paths, and insecure mobile API behavior.
Drafted detailed technical reports and executive summaries, translating technical findings into clear recommendations for engineering teams and C-suite leadership.
Mentored junior analysts and helped shape internal testing standards, methodology, and documentation processes.

Cyber Security Analyst — Zyston LLC

Dallas, TX — Jan 2019 – Dec 2020

Investigated and triaged security incidents using Splunk, QRadar, and AlienVault.
Analyzed host-based telemetry from CrowdStrike Falcon, Carbon Black, and Sumo Logic.
Performed threat hunting, wrote intelligence briefs, and assisted with incident response cases.
Trained new analysts on triage methodology, detection logic, and attacker behavior patterns.

Cyber Security Intern — Decypher Tech Ltd.

San Antonio, TX — Summer 2016

Assisted with web, internal, and external penetration tests across multiple industries.
Documented findings in Dradis and produced testing narratives for IT departments and executives.
Supported log aggregation and incident response using an ELK stack during a breach investigation.

Tools & Technologies

Cobalt Strike • Sliver • Burp Suite Pro • CrackMapExec / NetExec • Impacket • Evil-WinRM • Responder • ntlmrelayx • BloodHound • Go
Nmap • Nuclei • ffuf • Amass • Gobuster • OSINT frameworks
AWS CLI • PACU • MicroBurst • ScoutSuite • AzureHound • PowerZure
Python • Bash • PowerShell • Git • Dradis • AttackForge • PlexTrac

Projects & Research

Building an extended-range antenna for RFID badge cloning for the Proxmark3.
Writing a long-form research series on psychological principles of phishing.
Active in local San Antonio and Austin hacker meetups (AHA, SAHA, B-Sides).
Co-presented at B-Sides Toronto on Business Process Compromise methodologies.

Education

University of Texas at San Antonio — Bachelor of Arts in Psychology, Minor in Cyber Security (Dec 2018)

Contact

San Antonio, Texas

Phone: 210-364-7546

Email: jhasewinkle [at] proton [dot] me

LinkedIn: James Hasewinkle