Senior Cybersecurity Analyst — 24/7 Threat Detection & IR

Castelion; Torrance (CA); On-site; USD 120,000 - 180,000; Full time

Job summary

Castelion is seeking an experienced Senior Cybersecurity Analyst to join our team in Torrance, CA. You will protect high-sensitivity systems and data critical to national security, leading 24/7 monitoring, incident response, and threat hunting across complex environments.

The role emphasizes MITRE ATT&CK-aligned analysis, compliance with DoD frameworks (NIST 800-171, CMMC, DFARS, ITAR), and collaboration with IT, engineering, and program teams.

Qualifications

• 3+ years of experience in cybersecurity, information security, or related technical security roles
• Hands-on experience with security operations, incident response, and threat analysis
• Expert knowledge of security tools: SIEM (Splunk, QRadar, Sentinel), EDR (CrowdStrike, Carbon Black), IDS/IPS

Responsibilities

• Lead 24/7 security monitoring efforts using SIEM platforms and advanced threat detection tools
• Analyze security events, identify potential threats, and coordinate incident response activities
• Identify vulnerabilities and recommend remediation strategies for complex environments
• Analyze malware, APT tactics, and threat actor behavior
• Perform threat hunting activities to proactively identify sophisticated adversaries
• Conduct forensic analysis of security incidents involving classified and sensitive systems
• Contribute to compliance with NIST 800-171, CMMC, DFARS, ITAR, and other DoD requirements
• Contribute to and/or maintain security documentation including internal documentation, policies and procedures, incident reports, and audit artifacts
• Configure and maintain security tools including IDS/IPS, EDR, DLP, and vulnerability scanners
• Support secure architecture reviews across the organization
• Mentor junior analysts and contribute to team skill development
• Coordinate with IT, engineering, manufacturing, and program teams on security initiatives
• Participate in threat intelligence sharing with government and industry partners

Skills

SIEM platforms

EDR

IDS/IPS

MITRE ATT&CK

Threat intelligence

OSINT

Incident response

Scripting/automation

CUI protection

Clearance eligibility

Education

Degree in Cybersecurity/CS/Engineering

Tools

Splunk

QRadar

Sentinel

CrowdStrike

Carbon Black

Job description

Castelion is seeking an experienced Senior Cybersecurity Analyst to join our team in Torrance, CA. You will protect high-sensitivity systems and data critical to national security, leading 24/7 monitoring, incident response, and threat hunting across complex environments.

The role emphasizes MITRE ATT&CK-aligned analysis, compliance with DoD frameworks (NIST 800-171, CMMC, DFARS, ITAR), and collaboration with IT, engineering, and program teams.