Defensive Security

Defensive Security is a cybersecurity training company that delivers hands-on, lab-oriented security workshops under its "PurpleLabs" training portfolio. The company focuses on practical education using open source software, combining offensive and defensive techniques in a "purple team" format — meaning participants learn both attack methods and corresponding mitigation strategies simultaneously. Training topics covered include: - Linux system hardening and kernel-level security (Grsecurity/PaX/GCC hardening) - Active Directory and network services hardening - Mandatory Access Control and Linux namespaces/capabilities vs. exploits - Memory forensics using tools like the Volatility Framework against Linux rootkits - Web Application Firewall (WAF) and Database Activity Monitoring (DAM) vs. OWASP Top 10 vulnerabilities - Secure SSH relay configuration and defense-in-depth principles - Deep Packet Inspection (DPI) and PCAP analysis for malware detection - Runtime monitoring using Sysdig and SystemTap (stap) The company emphasizes minimal theory in favor of maximum hands-on lab time, drawing on over 20 years of experience in open source infrastructure security. Workshops are delivered by security professionals and are designed to build practical competency in a short timeframe. Clients include organizations from the financial sector (Alior Bank, Bank Millennium), energy (PGNiG), telecommunications (Cyfrowy Polsat), industrial automation (Rockwell Automation), and technology companies (Stack Overflow). The client base appears predominantly Polish, suggesting the company operates primarily in the Polish and Central European market.