Assumed Breach Simulation: Starting Inside to Test Detection and Response

Assumed breach simulation starts with the premise that an attacker has already gained initial access — through phishing, compromised credentials, or supply chain attack. The focus shifts from 'can we get in?' to 'once inside, can you detect us, and how far can we go before you respond?' Testing evaluates: lateral movement detection, privilege escalation alerting, data access monitoring, command-and-control communication detection, and the critical metric: dwell time — how long an attacker can operate inside your network before being detected.