Senior Threat Analyst

Role Summary

As a Senior Threat Analyst on our Managed Detection and Response (MDR) team, you will provide best-in-class monitoring, detection, and response services to proactively defend customer environments before attacks prevail. You will work alongside and contribute to a team of cyber threat hunters, incident response analysts, engineers, and ethical hackers by using enterprise, log analysis and endpoint collection systems to facilitate investigations, identification, and neutralization of cyber threats.

What You Will Do

• Monitor, investigate, and respond to alerts generated by the Sophos security stack (including EDR/XDR capabilities)
• Act as the escalation point for Tier I and Tier II Analysts, leading complex and high-severity investigations through to resolution
• Lead the technical response to major security incidents, coordinating containment and remediation activities with customers and internal teams
• Mentor and coach Tier I and Tier II Analysts, and quality-review case work to ensure thorough and accurate investigation practices
• Perform end-to-end analysis on suspicious activity to assess scope, impact, and risk
• Identify and respond to cyber threats across customer environments using approved playbooks and tooling
• Accurately document findings, investigative steps, and outcomes in the MDR case management platform
• Plan and lead hypothesis-driven threat hunts across the MDR customer base, informed by threat intelligence and adversary behavior
• Investigate phishing emails, suspicious binaries, and behavioral anomalies
• Drive detection improvements by identifying recurring false positives and coverage gaps, and by authoring or refining detection logic
• Stay informed on threat actor behaviors, MITRE ATT&CK techniques, and Sophos threat research updates
• Proactively research emerging IOCs, active exploits, and vulnerabilities to stay ahead of evolving threats
• Author and maintain playbooks, knowledge base articles, and documentation, and contribute to continuous improvement initiatives
• Participate in shift rotations and ensure timely, detailed handovers between global teams
• Manage case workflows: create cases, track progress, and follow up with clients until resolution
• Engage with clients in English and Japanese via chat, phone, and tickets, clearly explaining findings and recommended actions
• Contribute to the development of Security Operations processes and provide feedback on tooling

What You Will Bring

• 5+ years of hands-on experience in a Security Operations Center (SOC), Managed Detection and Response (MDR) environment, or cybersecurity-focused IT role
• Proven experience leading incident response efforts, including containment, mitigation, and recovery during active security incidents
• Strong experience with endpoint and network security tools (e.g., EDR, XDR, IDS/IPS, malware defense platforms), with the ability to validate and triage complex alerts
• Hands-on threat hunting experience, with a solid understanding of attacker behavior and patterns
• In-depth knowledge of adversary tactics and techniques such as obfuscation, persistence, privilege escalation, lateral movement, and defense evasion, and the ability to identify these in real-world environments
• Strong working knowledge of Windows operating systems (both workstation and server), with additional experience in Linux (Ubuntu, Debian, RedHat) or macOS environments
• Strong ability to analyze Windows event logs and other telemetry data
• Solid understanding of network traffic analysis, including TCP/IP, routing, switching, and protocols
• Experience mentoring, coaching, or reviewing the work of other analysts
• Excellent troubleshooting and analytical thinking skills, with attention to detail in investigations and case documentation
• Excellent written and verbal communication skills, with the ability to clearly explain findings to both technical and non-technical audiences
• Customer-first mindset with professionalism and a focus on service excellence
• Must thrive within a team environment as well as on an individual basis
• Natural curiosity and ability to learn new skills quickly in a fast-paced, ever-changing threat landscape
• A proactive approach to improving detections, processes, and tooling
• A passion for cybersecurity, continuous improvement, and staying current on threat trends
• Bachelor's degree in Information Technology, Computer Science, Cybersecurity or related field, or equivalent practical experience
• Business-level Japanese (JLPT N2 or above, or native) and business-level English, both written and spoken
• Willingness to participate in shift work including nights, weekends and holidays (our MDR service is 24x7x365)

Desirable

• Strong knowledge of the MITRE ATT&CK framework and its application in detection and response
• Experience working with SIEM platforms and managing enterprise security telemetry
• Ability to write and interpret SQL queries for data analysis and investigation
• Experience with OSQuery
• Programming and scripting skills, particularly in PowerShell
• Advanced cybersecurity certifications (e.g., GCIH, GCFA, GCIA, GREM, OSCP, CISSP, or similar)