Windows Network Security: NTLM Relay Attacks and Defenses

Windows Active Directory networks often rely on legacy authentication protocols, leaving them highly vulnerable to credential abuse. Understanding how NTLM relay attacks work is essential for anyone looking to secure modern enterprise environments or pursue a career in ethical hacking and network defense. In this text-based course, you will transition from understanding basic authentication flows to identifying, simulating, and defending against NTLM relay exploits. You will learn how to analyze network traffic for vulnerabilities, understand the mechanics of credential forwarding, and apply modern defense-in-depth strategies to protect domain resources. What you'll learn: • Understand the core mechanics of NTLM and NetNTLM authentication protocols. • Identify network configurations vulnerable to LLMNR, NBT-NS, and mDNS spoofing. • Execute simulated NTLM relay attacks against SMB, HTTP, and LDAP services. • Analyze captured network traffic to pinpoint weak authentication handshakes. • Implement robust mitigations including SMB signing, LDAP signing, and Extended Protection for Authentication (EPA). • Configure modern Windows security baselines to transition safely toward Kerberos-only environments. The course begins with foundational concepts of Windows network protocols and authentication handshakes. From there, you will progress through written step-by-step scenarios demonstrating relay techniques, culminating in practical mitigation strategies and modern security configurations. This course is designed for beginning cybersecurity students, junior system administrators, and aspiring penetration testers with no advanced prerequisites. Start reading today to master NTLM security and secure your network infrastructure.