Detection and Response Engineer (SPLUNK) in Chicago, Illinois at Coalfire Systems

We are seeking a Detection and Response Engineer to join our Defensive Services team, supporting SIEM monitoring and alerting, threat hunting, and purple team activities that help our clients meet both federal compliance and commercial security requirements. If you're passionate about defending organizations against evolving threats, driven to innovate, and thrive in a collaborative, high-performing environment, we'd love to have you on our team. Join us in our mission to make the world a safer place through proactive cybersecurity and operational excellence.

• Collect, analyze, and operationalize threat intelligence to inform proactive detection and threathunting activities, driving measurable security posture improvements across client environments.
• Develop, optimize, and maintain custom detection and threathunting queries across two or more SIEM platforms, tuning alerts for improved fidelity and building dashboards and saved searches that support repeatable, operational use cases.
• Plan and lead cyclical, hypothesisdriven threat hunts using threat intelligence and behaviorbased analytics; identify detection gaps and telemetry blind spots, and translate hunt outcomes into detection improvements, alert tuning, and updated runbooks.

• 2–4 years of experience operating within largescale enterprise security environments, including exposure to cloudhosted or hybrid infrastructures.
• Foundational working knowledge of at least one major cloud platform (Azure, AWS, or GCP) and how cloud telemetry is leveraged for security monitoring and investigations.
• Handson experience with at least two SIEM platforms (e.g., Splunk, Microsoft Sentinel, ELK, LogRhythm, or Sumo Logic) in a production detection and response environment.
• Experience independently monitoring, validating, and escalating SIEM alerts in accordance with documented runbooks, SLAs, and severity thresholds.
• Proven ability to independently investigate and respond to security alerts, performing deepdive analysis across multiple log sources to determine scope, root cause, and impact.
• Experience escalating confirmed or highconfidence incidents with clear timelines, evidence, and MITRE ATT&CK mapping to Incident Response teams or senior engineers.
• Experience conducting structured and cyclical threathunting activities using hypothesisdriven and behaviorbased methodologies.
• Ability to leverage threat intelligence to understand threat actor tradecraft, attack chains, and expected telemetry, and apply that knowledge to investigations and hunts.
• Handson experience developing, optimizing, and maintaining custom detection and threathunting queries in at least two SIEM platforms, and translating investigative requirements into performant, reusable query logic.
• Experience identifying detection gaps, telemetry blind spots, and data quality issues, and translating findings into alert tuning, new detection logic, dashboards, and updated runbooks or SOPs.
• Excellent communication, organizational, and problem-solving skills, with the ability to convey complex technical information clearly.
• Strong documentation skills for creating technical diagrams, written descriptions, and other supporting materials.
• Demonstrated ability to work both independently and as a member of a team, maintaining a professional attitude and demeanor.
• Critical thinking skills to balance robust security requirements against mission objectives.
• Proven track record of adapting quickly and efficiently in fast-paced, dynamic environments.
• Experience utilizing a Detection-as-Code framework
• Experience working with NIST 800-53 environments

REQUIRED CERTIFICATIONS:

At least one of the following:

• Splunk Enterprise Certified Administrator

• Splunk Enterprise Security Certified Administrator

• SumoLogic Administrator

• Microsoft Security Operations Associate

• Elastic Stack Certified Administrator

• Professional services background: Prior experience supporting external clients from within a consulting or professional services organization.
• Automation capabilities: Experience automating workflows in GitLab or GitHub with Terraform and Ansible.
• Compliance frameworks: Understanding of FedRAMP, FISMA, HIPAA, HITRUST, PCI, and similar regulatory standards.