Senior Threat Researcher @ Sophos

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

As a Threat Researcher, you will be part of the front line responsible for helping to protect millions of users worldwide from network security threats and exploits. The successful candidate will analyze and detect the latest threats and help create the next generation of SophosLabs research tools. The ideal candidate is passionate about computer network security and has a high aptitude for solving challenging puzzles, with strong attention to detail.
What you will do

Must be able to conduct in-depth research on emerging network-, software-, and application-based security threats, threat actors, vulnerabilities, and malware campaigns.

Must be able to reproduce and simulate attack techniques, reverse engineer exploits and PoC code, etc., in lab environments to understand their network signatures and develop protection rules that ensure thorough detection and coverage.

Continuously monitor critical threat intelligence sources to stay on top of emerging threats and trends.

Develop high-quality detection/IPS signatures to detect and prevent threats and exploits.

Build, test, and publish detection/IPS signatures.

Must be able to write high-quality threat or exploit descriptions based on research, including white papers, blog posts, and case studies.

Track zero-day and newly discovered vulnerabilities and malware on a regular basis, and strive to provide timely protection for customers.

Independently conduct research and reverse engineer threats and exploits, and be able to provide detailed research reports.

Triage requests submitted by other departments, respond to tasks, and escalate complex issues to senior team members.

Answer customer queries routed through Technical Support, as well as internal queries from all departments.

Identify opportunities to write blogs for the Sophos website to raise customer awareness.

Understand gaps or failures and provide technical insights while working with engineering teams to develop solutions that improve future test results.

Maintain aligned communication with the team, including updates on quality, effectiveness, and third-party test issues.

Work with third-party test coordinators to improve performance in external test results.

Take initiative and drive quality and effectiveness.

Mentor and coach other Threat Researchers on writing and content creation.

What you will bring

8+ years of experience in threat (vulnerability and exploit) research and threat intelligence, with in-depth knowledge of the latest cyber threats, threat actors, and attack techniques.

In-depth knowledge of networking fundamentals, including the OSI model.

Strong, practical understanding of the TCP/IP protocol suite and low-level evasion techniques.

Good understanding of L2, L3, and L4 network communication.

Strong understanding of L7 protocols and upper-level OSI evasion techniques, such as HTTP, SMTP, POP3, DNS, Telnet, HTTPS/SSL, and FTP.

Deep understanding of network evasion techniques.

Experience in detecting and reproducing network attacks, such as vulnerability exploitation, system discovery, and lateral movement techniques.

Ability to decode network traffic using packet analyzer tools such as Wireshark, Ethereal, and tcpdump.

Strong understanding of exploits (file- and protocol-based), network evasion techniques, and the Linux network stack.

Strong understanding and ability to develop and test IPS signatures (preferably using Snort).

Experience in developing Snort IPS signatures/rules.

Good understanding of Snort engine internals.

Good understanding of various network and endpoint security technologies, such as conventional firewalls, NGFWs, IDS/IPS, and proxy servers.

Strong, practical understanding of commonly used techniques such as Cross-Site Scripting (XSS), SQL Injection, Cross-Site Request Forgery (CSRF), Directory Traversal, and Buffer Overflow.

Proficient in at least one scripting or programming language (e.g., Python, Shell).

Familiarity with software development tools such as GitLab and GitHub.

Familiarity with Sophos or other competitor firewall products.

Bachelor’s or Master’s degree in Engineering, Computer Science, or Electronics.

Good to have certifications such as CEH, CCNA/CCNP, and CISSP.

LI-Remote #B2
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.
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