Senior Threat Behavior Researcher (UK)

About UsSophos is a global leader and innovator of advanced security solutions for defeating cyberattacks. The company acquired Secureworks in February 2025, bringing together two pioneers that have redefined the cybersecurity industry with their innovative, native AI-optimized services, technologies and products. Sophos is now the largest pure-play Managed Detection and Response (MDR) provider, supporting more than 28,000 organizations. In addition to MDR and other services, Sophos’ complete portfolio includes industry-leading endpoint, network, email, and cloud security that interoperate and adapt to defend through the Sophos Central platform. Secureworks provides the innovative, market-leading Taegis XDR/MDR, identity threat detection and response (ITDR), next-gen SIEM capabilities, managed risk, and a comprehensive set of advisory services. Sophos sells all these solutions through reseller partners, Managed Service Providers (MSPs) and Managed Security Service Providers (MSSPs) worldwide, defending more than 600,000 organizations worldwide from phishing, ransomware, data theft, other every day and state-sponsored cybercrimes. The solutions are powered by historical and real-time threat intelligence from Sophos X-Ops and the newly added Counter Threat Unit (CTU). Sophos is headquartered in Oxford, U.K. More information is available at www.sophos.com.

Role Summary

Malware Researcher? Red/Blue/Purple team member? We have a fantastic opportunity here at Sophos Labs for a Threat Researcher role to join our global team of Behavioral Protection engineers, to hunt, to research, and to add real-time protection for suspicious activity across our customer environments. Our team of skilled security experts combine their passion to detect & disrupt cyber-attacks with their capability to develop protection rules that can cut through the noise in modern computing environments to tease out attacker’s nefarious activities. You are intrinsically motivated to understand the core logic behind malware and hacking attacks, to find & predict new ways attackers will modify their techniques and take great satisfaction in developing robust protection logic that is immune to evasive actions. You will be responsible for writing behavioral protection rules that are able to block malicious activities across all types of TTP (even if a Mitre Technique doesn’t exist yet). This is the foundation of Sophos next-gen approach. Above all - you enjoy thinking creatively; combining your deep technical knowledge, your tenacity for innovation, and your can-do attitude to solve complex and challenging problems on daily basis. Additionally, you will also be supporting our remediation effort to remove artifacts left behind, by writing cleanup rules, and supporting our Sandbox development, such as (but not limited to) creating signatures, identifying evasion techniques that prevent the sandbox from running the threat smoothly. What You Will Do

Conduct in-depth behavioral analysis of Windows threats.

Develop Behavioral rules for various threat behaviors including hands-on keyboard attack, malware payloads, initial attack vectors and Advanced Persistent Threats (APTs).

Produce quality threat analysis reports for both internal and external audience.

Assist in sandbox improvements by analyzing malware that hinders the sandbox environment in running the threat, which deploys various anti-analysis techniques.

Develop Cleanup rules to remove artifacts that are left behind by the behavioral protection rules.

Collaborate with other cross-functional teams to improve behavioral protection capability based on the threat analysis.

Guide and train junior team members in assisting malware analysis, peer code review.

Assist in the development of tools wherever necessary to improve day-to-day task.

What You Will Bring

Strong knowledge of Windows Internals including Memory management, Processes, Threads.

Proficiency in both static and dynamic analysis of threats, using tools such as IDAPro, WinDbg.

Demonstrated programming experience. Preferred: Python, Lua.

Excellent communication skills with the ability to demonstrate complex technical problem to peer researchers as well as to product engineering team.

Excellent analytical and problem-solving skills with the ability to think strategically and creatively.

Bachelor’s degree in computer software (Computer Security preferable) or equivalent experience.

Ready to Join Us?At Sophos, we believe in the power of diverse perspectives to fuel innovation. Research shows that candidates sometimes hesitate to apply if they don't check every box in a job description. We challenge that notion. Your unique experiences and skills might be exactly what we need to enhance our team. Don't let a checklist hold you back – we encourage you to apply. What's Great About Sophos?· Sophos operates a remote-first working model, making remote work the primary option for most employees. However, some roles may necessitate a hybrid approach. While we are a remote first organization, applicants must have legal authorization to work in the jurisdiction where the position is posted, without requiring employer sponsorship.· Our people – we innovate and create, all of which are accompanied by a great sense of fun and team spirit· Employee-led diversity and inclusion networks that build community and provide education and advocacy· Annual charity and fundraising initiatives and volunteer days for employees to support local communities· Global employee sustainability initiatives to reduce our environmental footprint· Global fitness and trivia competitions to keep our bodies and minds sharp· Global wellbeing days for employees to relax and recharge · Monthly wellbeing webinars and training to support employee health and wellbeing Our Commitment To YouWe’re proud of the diverse and inclusive environment we have at Sophos, and we’re committed to ensuring equality of opportunity. We believe that diversity, combined with excellence, builds a better Sophos, so we encourage applicants who can contribute to the diversity of our team. All applicants will be treated in a fair and equal manner and in accordance with the law regardless of gender, sex, gender reassignment, marital status, race, religion or belief, color, age, military veteran status, disability, pregnancy, maternity or sexual orientation. We want to give you every opportunity to show us your best self, so if there are any adjustments we could make to the recruitment and selection process to support you, please let us know. Data ProtectionIf you choose to explore an opportunity, and subsequently share your CV or other personal details with Sophos, these details will be held by Sophos for 12 months in accordance with our Privacy Policy and used by our recruitment team to contact you regarding this or other relevant opportunities at Sophos. If you would like Sophos to delete or update your details at any time, please follow the steps set out in the Privacy Policy describing your individual rights. For more information on Sophos’ data protection practices, please consult our Privacy Policy Cybersecurity as a Service Delivered | Sophos Apply To This Job