Yurii Sanin
Yurii Sanin is a senior security consultant with K2 Integrity/Leviathan Security Group. A member of the firm’s Technical Services team, Yurii specializes in white- and black-box penetration testing and delivers security assessments across web, API, cloud, and mobile applications. His work includes in-depth source code reviews, architecture analysis, and security research and development (R&D), with […]
Mark Rosnick
Mark Rosnick is a security consultant at K2 Integrity/Leviathan Security Group. With more than 25 years of experience defending computer systems, Mark focuses on offensive security, performing penetration tests across cloud infrastructure platforms, global data networks, web frameworks and applications, gaming systems, operating systems, and embedded hardware and firmware. He identifies and exploits low-level vulnerabilities […]
Serhii Romanko
Serhii Romanko is a senior security consultant at K2 Integrity/Leviathan Security Group, where he provides security architecture guidance and conducts comprehensive security assessments across applications and cloud environments. With almost a decade of cybersecurity experience, he conducts black- and white-box penetration testing, source code review, and security configuration reviews of cloud platforms, including AWS and […]
Viktoriia Reitsenshtein
Viktoriia Reitsenshtein is a senior security consultant at K2 Integrity/Leviathan Security Group. She provides security architecture guidance and performs black-, gray-, and white-box penetration testing of applications. Her work also includes security research and development, as well as training and mentoring junior security consultants. Her technical expertise spans web and mobile application penetration testing, cloud […]
Amina Murtazina
Amina Murtazina is a security consultant with K2 Integrity/Leviathan Security Group, where she provides expertise across a broad spectrum of cybersecurity disciplines. Her work spans security architecture guidance, black- and white-box application penetration testing, auditing, and security research and development. She supports clients in strengthening their security posture by applying a rigorous approach to identifying […]
Jeffery Frazier
Jeffery Frazier is a security consultant and a member of K2 Integrity/Leviathan Security Group’s Technical Services team. He specializes in hardware and application security penetration testing and security evaluations, bringing nearly two decades of hands-on experience across secure development, offensive and defensive tool engineering, and secure command-and-control communications systems. Jeffery’s technical expertise spans application and […]
A.J. Butt
A.J. Butt is a security consultant with K2 Integrity/Leviathan Security Group, delivering technical security services across a wide range of project sizes and practice areas. His work includes black- and white-box web application and web services testing, internal and external network infrastructure testing, cloud configuration review, adversary simulation, native device and host review, and source […]
Vitalii Asieiev
Vitalii Asieiev is a security consultant with K2 Integrity/Leviathan Security Group, with a focus on security architecture guidance, black‑ and white‑box application penetration testing, auditing, and security research and development. Vitalii leads research and development initiatives focused on the security of web, API, and cloud‑based systems in commercial environments, identifying security risks, developing proof‑of‑concept exploits, […]
Andrii Apostol
Andrii Apostol is a software engineer with K2 Integrity/Leviathan Security Group, with expertise in system architecture, distributed computing, and high-performance enterprise solutions. He brings a broad technological background that includes .NET and Node.js development, SQL/NoSQL databases, microservices, and DevOps automation, enabling him to build scalable, secure, and resilient systems across diverse technology environments. With a […]
Sofia Aberegg
Sofia Aberegg is a security consultant in K2 Integrity/Leviathan Security Group’s Technical Services team, specializing in web application penetration testing, exploit development, and secure code review. She brings deep technical expertise across offensive security testing, secure development practices, and vulnerability research to help organizations identify and mitigate complex security risks. In addition to client engagements, […]