Senior Threat Analyst

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)