Senior Cyber Defense Engineer – Boundary & Cloud Countermeasures

Quantum Sky; Pearl City (HI); On-site; USD 95,000 - 120,000; Full time

Job summary

Quantum Sky seeks an experienced Cyber Countermeasure Specialist to join the DCO team supporting DISA PAC at Ford Island, Pearl Harbor-Hickam, HI. You will engineer deployment of custom detection signatures, firewall rules, and automated blocking across global sensors and cloud environments up to TS/SCI.

Responsibilities include lifecycle management of detections, threat intelligence translation, threat hunt automation, and regulatory reporting.

Qualifications

• Level II: Bachelor’s degree in Cybersecurity, Computer Science, Computer Engineering, Information Systems, or related field with 2+ years in CND or security tool engineering; OR Associate with 4+ years; OR 6+ years in lieu of a degree.
• Level III: Bachelor’s with 4+ years of relevant experience; OR Associate with 6+ years; OR 8+ years in lieu of a degree.
• Must hold DoD 8140.03 / DCWF Work Role Code 521 certification prior to start; accepted certifications include Security+ CE, CySA+, CCNA-Security, CND, SSCP, GICSP, GSEC, CASP+ CE, CCNP Security, GCIA, GCIH, CISSP.
• Ability to obtain CE certification within 6 months of start (e.g., Cisco Certified CyberOps Associate/Professional, Cisco FirePOWER).
• Proven experience writing, testing, deploying custom intrusion signatures (Snort, Suricata, YARA) and firewall/ACL rule configurations.
• Working knowledge of Cisco FirePOWER Management Center, IDS/IPS, and proxy/web content filtering.
• Deep understanding of TCP/IP, UDP, ICMP, DNS, HTTP/S, TLS; packet inspection tools (Wireshark, tcpdump).
• Familiarity with MITRE ATT&CK and threat hunter methods.
• Willingness for on‑call rotation for after‑hours incidents.
• U.S. citizen.

Responsibilities

• Bridge threat intelligence, incident analysis, and active network defense.
• Engineer, test, validate, deploy, de-conflict, and track lifecycle of custom detection signatures, firewall rules, and mitigation actions across boundary sensors and networks.
• Analyze telemetry from automated blocking tools and refine blocking to reduce false positives/negatives.
• Track countermeasures and document changes to maintain synchronized defensive posture.
• Execute rapid rollback and adhere to government network freeze conditions when needed.

Skills

DODIN/DISN knowledge

Threat intel to active defense

Snort/Suricata/YARA rule writing

Cisco FirePOWER FMC experience

Wireshark/tcpdump

On-call readiness

US Citizen

Education

Bachelor’s or higher in Cybersecurity/CS/Engineering

Associate degree with 4+ years or 6+ years experience

Tools

Cisco FirePOWER Management Center

IDS/IPS / Firewall configurations

Multi-cloud security (AWS/Azure/GCP/OCI)

SOAR playbooks (Cortex XSOAR, Splunk SOAR)

Rally/DoDI incident tracking

Job description

Quantum Sky seeks an experienced Cyber Countermeasure Specialist to join the DCO team supporting DISA PAC at Ford Island, Pearl Harbor-Hickam, HI. You will engineer deployment of custom detection signatures, firewall rules, and automated blocking across global sensors and cloud environments up to TS/SCI.

Responsibilities include lifecycle management of detections, threat intelligence translation, threat hunt automation, and regulatory reporting.