Senior Cyber Threat Hunter

Job Description

 Appealing Points:

• Lead proactive threat hunting to identify and mitigate advanced cyber threats across a cutting-edge mobile network environment.
• Work across advanced security domains including MITRE ATT&CK, 4G/5G, SS7, Diameter, GTP, Kubernetes, AWS/Azure/GCP, SIEM, UEBA, and forensic analysis.
• Leverage AI/ML and LLM capabilities to enhance threat hunting, automate analysis, and improve operational efficiency.

Annual salary : 7 Million Yen and Above.

Job Responsibilities:.

• Develop and execute hypothesis-driven proactive threat hunting campaigns using log, endpoint, and network data.
• Research and track adversary Tactics, Techniques, and Procedures (TTPs) using frameworks such as MITRE ATT&CK.
• Translate hunting outcomes into actionable security improvements, including detection logic, data requirements, false-positive guidance, and validation steps.
• Collaborate with Detection Engineering teams to improve detection rules, playbooks, and hunting methodologies.
• Partner with Cyber Threat Intelligence, Incident Response, and SOC teams to operationalize threat insights and support incidents, investigations, and containment.
• Conduct technical analysis of attacker tradecraft, including lateral movement, persistence, and exfiltration.
• Utilize advanced security tools such as SIEM, UEBA, and forensic analysis platforms.
• Automate analysis and detection processes using Python, PowerShell, and similar scripting languages.
• Stay current with evolving threats and emerging adversary techniques.

Job Qualifications:

• Education:
  • Bachelor’s degree in Computer Science, Cybersecurity, Information Systems, or a related field, or equivalent practical experience.
• Technical Skills & Knowledge:
  • In-depth knowledge of the MITRE ATT&CK framework.
  • Strong understanding of enterprise network architecture, including TCP/IP, routing, firewalls, VPNs, networking protocols, deep packet inspection, and network traffic analysis.
  • Expertise in telecommunications protocols and mobile infrastructure, particularly 4G/5G, SS7, Diameter, and GTP.
  • Deep understanding of cloud-native environments, Kubernetes, and container orchestration, including threat hunting in these environments.
  • Experience with major cloud platforms such as AWS, Azure, and GCP and their native security services.
  • Experience and strong interest in using AI, ML models, and LLMs for threat hunting and automation.
• Soft Skills:
  • Exceptional analytical, critical-thinking, and problem-solving skills with strong attention to detail.
  • Knowledge of secure architecture and design principles.
  • Excellent written and verbal communication skills.
  • Strong documentation discipline.
  • Ability to work effectively in a fast-paced operational environment, including flexibility for non-standard hours during cybersecurity incidents.
  • Strong aptitude for continuous learning and adapting to new technologies and threat landscapes.
  • Understanding of cybersecurity-related regulatory compliance and data privacy requirements.

Preferred Qulifications:

• Industry certifications such as SANS FOR508 and CISSP.

Language Requirements: Advanced Business level English 

About Company:

The largest eCommerce company in Japan, and the third-largest eCommerce marketplace company worldwide. The organization provides a variety of consumer and business-focused services including e-commerce, e-reading, travel, banking, securities, credit card, e-money, portal and media, online marketing, and professional sports.  The company is expanding globally and currently has operations throughout Asia, Western Europe, and the Americas. 

[Measures against passive smoking]

No smoking indoors allowed

Designated smoking area