Defensive Security

Defensive Security is a security company founded by Leszek Miś, who is also its principal trainer and researcher. It offers tools, detections, courses and research based on how real attackers work today.

What Defensive Security offers

• PurpleLabs Cyber Range — a live lab where users run attacks, detect them and build defences.
• Hands-on courses — practical training for security staff.
• EDRmetry — a tool that generates telemetry for detection testing.
• Linux forensics and threat hunting — covering memory analysis and persistence.

Who it works with

The content targets red and blue teams, particularly people working with Linux and cloud-native systems.

Key facts

• Founder experience: more than 15 years in cyber security
• Approach: purple teaming, where simulation feeds detection
• Focus: Linux, Kubernetes and eBPF