Alan Ledesma
Chicago,IL
Summary
Security Engineer with experience in endpoint detection and response (EDR), incident response, identity security, email security engineering, and vulnerability management. Leads investigations into phishing, business email compromise, and account compromise incidents while supporting internal, external, and web application penetration testing engagements. Designs and advises on Microsoft Entra security hardening, Conditional Access, MFA enforcement, and risk mitigation strategy. Combines offensive security expertise with defensive operations to improve enterprise security posture and reduce organizational attack surface.
Overview
1
1
Certification
2
2
years of professional experience
Work History
Security Engineer
Proven IT
05.2025 - Current
- Engineer and improve enterprise email security controls through the implementation and administration of ProofPoint, Sublime Security, and KnowBe4, reducing phishing risk and strengthening organizational defense against email-based threats.
- Investigate and triage endpoint, identity, and cloud security alerts within CrowdStrike Falcon and Microsoft Entra, performing analysis, containment, remediation, and escalation of security incidents.
- Managed incident response cases, including phishing, account compromise, and business email compromise (BEC) investigations, conducting mailbox scoping, log analysis, credential resets, and account hardening activities to strengthen organizational security posture.
- Scope and support internal, external, and web application penetration testing engagements, assisting with vulnerability validation, attack surface analysis, and client-facing reporting.
- Advised clients on Microsoft Entra and Microsoft 365 security hardening, focusing on Conditional Access policy design, MFA enforcement, identity protection, and access control best practices to enhance overall security framework.
- Completed cybersecurity insurance assessments, security questionnaires, and risk evaluations to align client environments with security, compliance, and cyber insurance requirements, supporting risk mitigation efforts.
Cybersecurity Specialist
Preferred Communications Systems
09.2024 - 04.2025
- Investigated and responded to security alerts across endpoint and network environments, performing threat analysis and coordinating remediation efforts to enhance compliance.
- Conducted vulnerability and risk assessments to identify critical exposures, prioritizing remediation and implementing manual and automated strategies to strengthen client system security.
Education
Bachelor of Science - Information Technology
Governors State University
University Park, IL05-2027
Associate of Applied Science - Information Technology
Prairie State College
Chicago Heights, IL03-2023
Associate of Science - Kinesiology
Prairie State College
Chicago Heights, IL03-2013
Skills
Security operations: CrowdStrike, Microsoft Entra, Incident response and identity management
Offensive security: Burp Suite, Cobalt Strike,
Active Directory exploitation
Vulnerability management: Nessus risk prioritization and remediation
Programming and scripting: Python
Domains: Web application security and network security
Domains: Web Application Security, Network
Security
Certification
- OffSec Certified Professional+ (OSCP+) - OffSec (09/2026 - 09/2029)
- Hack The Box Certified Penetration Testing Specialist - Hack the Box (10/21/2024)
- Hack The Box Certified Web Exploitation Specialist - Hack the Box (04/15/2025)
- Red Team Operator - Zero-Point Security LTD (03/30/25)
- CompTIA PenTest+ CompTIA (10/18/2025 - 10/18/2025)
- CompTIA CySA+ - CompTIA (03/2025 - 03/2028)
- CompTIA Security+ - CompTIA (06/2023 - 06/2026)
Projects
Bug Bounty & Security Research (Ongoing)
• Active security researcher on HackerOne, identifying web application vulnerabilities through manual testing and targeted exploitation techniques.
• Perform application-layer assessments using Burp Suite, custom payload development, and fuzzing methodologies to uncover logic and access control flaws.
Timeline
Security Engineer
Proven IT
05.2025 - Current
Cybersecurity Specialist
Preferred Communications Systems
09.2024 - 04.2025
Bachelor of Science - Information Technology
Governors State University
Associate of Applied Science - Information Technology
Prairie State College
Associate of Science - Kinesiology
Prairie State College