Endpoint Security Engineer

Reston, VA Contract On-Site Flexibility/Remote: 100%

Endpoint Security Engineer

As an Endpoint Security Engineer, you will design, deploy, and operationalize active, behavior-based endpoint detection and response (EDR/XDR) capabilities across one of the largest private operational fleets in North America. Protecting an enterprise comprising 600,000+ employees and 30,000+ physical sites, you will maintain rigorous security posture across traditional end-user computing (EUC) devices (laptop, desktop, mobile devices & retail terminals), on-premise physical & virtual servers & containerized workloads, and dynamic multi-cloud workloads (AWS, Azure, GCP).

In this role, you will balance proactive protection with business continuity—partnering directly with end-users and application owners to tune policies and eliminate operational friction, while providing tier-3/tier-4 technical escalations to Security Operations Center (SOC) analysts and IT Operations staff during active investigations.

Duties and Responsibilities

Fleet-Wide Behavioral Defense & Control Engineering

Engineer, deploy, and maintain Next-Gen Antivirus (NGAV) and Endpoint Detection & Response (EDR/XDR) agents (e.g., CrowdStrike Falcon, Microsoft Defender for Endpoint, SentinelOne) across hundreds of thousands of heterogeneous endpoints.

Implement active behavioral protections against zero-day malware, living-off-the-land binaries (LotLBs), fileless execution, and credential dumping.

Application Owner & End-User Engagement (Business Impact Management)

Serve as the primary technical partner to application owners and business units, establishing baseline behavior profiles to minimize false positives, performance degradation, or operational downtime across critical retail, logistics, and supply chain applications.

Manage allowlisting, exception workflows, and phased ring deployments (canary/pilot/production) to ensure silent, high-efficacy protection without disrupting day-to-day warehouse or logistics operations.

SOC & IT Operations Event Investigation Support

Act as endpoint security escalation lead for SOC analysts during high-severity threat detection and response events.

Act as endpoint operations escalation lead for IT administrators during high-impact event investigation and remediation efforts.

Perform advanced host forensics, process-tree reconstruction, memory analysis, and script-based live remediation (e.g., host isolation, automated artifact collection, registry rollbacks).

Hybrid & Multi-Cloud Workload Protection

Extend endpoint security standards across private data center virtualization layers (VMware/Nutanix) and episodic multi-cloud infrastructure (EC2, Azure VMs, Compute Engine, containerized hosts).

Control Efficacy & Continuous Validation

Continuously measure and test security control efficacy using automated attack simulation (Client) tools and Purple Team exercises.

Track and report on agent health, tamper-resistance, telemetry pipeline integrity, and coverage metrics aligned with enterprise asset management systems.

Required Knowledge, Skills, and Abilities (KSAs)

Technical Skills

EDR/XDR Engineering: Expert-level proficiency administering enterprise-scale endpoint platforms across Windows, macOS, Linux distributions, and container runtime environments.

Behavioral Analysis & Threat Hunting: Deep mastery of process lineage, behavioral IOAs (Indicators of Attack), Sysmon telemetry, and detection authoring using query languages such as SQL, KQL (Kusto Query Language), Splunk SPL, or YARA.

Hybrid Infrastructure & OS Internals: Deep understanding of Windows/Linux kernel architectures, API hooking, hypervisor isolation, and multi-cloud workload identity integrations.

Automation & Scripting: Strong programming/scripting abilities in PowerShell, Python, or Bash to orchestrate fleet-wide remediations and automate policy compliance at scale.

Artificial Intelligence & Machine Learning: Fluency applying appropriate AI/ML technologies and analytics platforms (Splunk, Databricks, Elastic) to streamline and/or automate activities including but not limited to research, developing documentation, and supporting development of executive communications. Fluency applying appropriate AI/ML technologies to automate security activities to improve timeliness or full automation of event response activities.

Abilities & Core Competencies

Stakeholder Empathy & Impa