Case Study: Leading U.S. Hospital and Healthcare System achieves verified remediation of critical ZeroLogon vulnerabilities with Horizon3.ai's NodeZero

Healthcare Faces an Aggressive Threat Landscape

Leading U.S. Hospital and Healthcare System, a top-rated care provider, faced an aggressive threat landscape and strict compliance requirements (HIPAA, PCI) despite having firewalls, EDR, patch management, network segmentation, and an MSSP. Seeking validation that patches and controls actually prevented attacks, the health system — with Liberman Networks — engaged Horizon3.ai and its NodeZero autonomous penetration-testing SaaS to assess defenses from an attacker’s perspective.

Horizon3.ai’s NodeZero ran a non-disruptive, eight-day autonomous test, mapping 8,411 hosts and identifying 31 vulnerabilities with 278 unique attack paths; it flagged 10 domain controllers vulnerable to ZeroLogon (initially appearing patched) and revealed an EDR misconfiguration that had blocked updates for 18 months. With Horizon3.ai and Liberman Networks’ guidance the hospital remediated the issues, NodeZero validated fixes (after an additional retest showed 4 of 10 remained exploitable until manually patched), and the organization improved monitoring, processes and confidence—adopting regular post-patch pentesting to reduce real-world risk.