Senior Threat Analyst

About Us Sophos is a cybersecurity leader defending 600,000 organizations globally with an AI-driven platform and expert-led services. Sophos meets organizations wherever they are in their security maturity and grows with them to defeat cyberattacks. Its solutions combine machine learning, automation, and real-time threat intelligence with frontline human expertise from Sophos X-Ops to deliver advanced, 24/7 threat monitoring, detection, and response. Sophos offers industry-leading managed detection and response (MDR) alongside a comprehensive portfolio of cybersecurity technologies — including endpoint, network, email, and cloud security, extended detection and response (XDR), identity threat detection and response (ITDR), and next-gen SIEM. Together with expert advisory services, these capabilities help organizations proactively reduce risk and respond faster, with the visibility and scalability needed to stay ahead of evolving threats. Sophos goes to market with a global partner ecosystem, including Managed Service Providers (MSPs), Managed Security Service Providers (MSSPs), resellers and distributors, marketplace integrations, and cyber risk partners, giving organizations the flexibility to choose trusted relationships when securing their business. Sophos is headquartered in Oxford, U.K. More information is available at . 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 an