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BSG Team

Who Are We

Berezha Security Group is a cybersecurity consulting firm focused on application security, penetration testing, social engineering, cybersecurity consulting, and professional training.

Our story

Our story began in 2014 when three prominent Ukrainian cybersecurity professionals have founded Berezha Security. Since then, our company has delivered over 120 projects to more than 80 clients worldwide. We have customers in all major business sectors, including IT services, software products, banking, fintech, retail, healthcare, media, gaming, consulting services, legal and advisory, and many more. Review our public references on Clutch to get a better view of our clients.

Using our offensive mindset and experience, we help our customers develop a mindful approach to cybersecurity and integrate security principles into all aspects of their business.

Our story

We empower our clients to defeat tomorrow’s cybersecurity threats – today.

Our certificates

Our contribution

  • We facilitate the cybersecurity industry development by supporting professional events.
  • We are at the core of OWASP Kyiv, OWASP Ukraine, and NoNameCon.
  • We speak at IT events and promote cybersecurity across the industries.
  • Bru Con
  • no name con
  • Owasp Ukraine
  • Owasp Kyiv

Our leadership team

Vlad Styran
Vlad Styran

Co-founder & CEO OSCP, CISSP, CISA

BSG business and cybersecurity strategist.
Cybersecurity expert, ethical hacker, keynote speaker, trainer, and consultant.

Vlad Styran
Co-founder & CEO

Vlad Styran is an internationally known cybersecurity professional with 15+ years of experience in Penetration Testing, Social Engineering, and Security Awareness. He currently holds OSCP, CISSP, and CISA credentials and was certified as C|EH, ISO27001LA, and many more throughout his career.

Vlad is a co-founder of the OWASP Kyiv chapter and the NoNameCon cybersecurity conference. He is a notable blogger, podcaster, and conference speaker.

At BSG, Vlad is responsible for our growth and customer experience. His involvement allows us to deliver first-rate cybersecurity consulting services in software security, cybersecurity awareness, cybersecurity strategy, and security investment.
Kostiantyn Korsun
Kostiantyn Korsun

Co-founder & COO

BSG Executive Director and business leader.
Cybersecurity expert, keynote speaker, and public figure.

Kostiantyn Korsun
Co-founder & COO

As former deputy head of Cybercrime Division at Security Service of Ukraine, Kostyantyn is a co-founder and the first head of CERT-UA. After resigning, Kos acted as Regional Director for the Ukrainian Research Office at iSIGHT Partners, an international cyber threat intelligence firm later acquired by FireEye Inc.

He is a prominent Ukrainian cybersecurity community member, a co-founder and the first Chairman of the Ukrainian Information Security Group (UISG), and a long-term head organizer of the UISGCON professional conference.

In BSG, he acts as an Executive Director and expert coach for the team, who shares his vast experience in cybersecurity, cybercrime research, and threat analysis.
Andriy Varusha
Andriy Varusha

Co-founder & CSO CISSP

BSG services, operations, and quality leader.
IT auditor and cybersecurity consultant.

Andriy Varusha
Co-founder & CSO

Andriy is an accomplished manager with 10+ years of experience in various industry verticals. He has started his IT Audit and Consulting career and continued in Enterprise IT and Software Development services.

Andriy has experience in leading customer relationships within the US, UK, and Western Europe geographies, responsible for distributed teams and permanent engagements of different scales.

Andriy has stood at the root of the Ukrainian cybersecurity professional community and has joined BSG to advance his contribution to the cybersecurity industry's development.
At BSG, Andriy leads the Project Management Office and acts as a security consulting practice lead.