Petra Security

Founded in 2023 by cybersecurity veterans from Abnormal Security, Palo Alto Networks, and Bridgewater, Petra Security has rapidly established itself in the competitive landscape of identity threat detection. The San Francisco-based company completed Y Combinator's Winter 2024 batch and has achieved mid-seven-figure annual recurring revenue within its first year, protecting over 2.5 million users across more than 10,000 businesses.

Petra Security's platform is purpose-built for Microsoft 365 environments, addressing sophisticated phishing attacks that bypass conventional defenses. Its AI-powered behavioral detection engine analyzes 30 times more data than traditional ITDR solutions, identifying threats that leverage residential proxies, valid sessions, and credentials that have already passed multi-factor authentication. The company operates at the intersection of AI, email security, and identity threat detection and response.

Beyond detection, Petra Security provides end-to-end remediation that reverses attacker actions across sessions, devices, inbox rules, and registered applications. The platform also generates forensic reporting with root-cause analysis, attacker timelines, and documentation suitable for compliance and insurance requirements - a capability that distinguishes it in the managed security space.