Mark Simos is an Architect with Microsoft Enterprise Services’ Cybersecurity Practice where he is part of a group of cybersecurity experts who consult for government, education, and commercial customers around the world as trusted cybersecurity advisors. Mark and his teammates deliver unique cybersecurity services and solutions to Microsoft’s customers. Mark is a recognized expert in credential theft attacks and defenses with real-world experience defending against them. He has co-authored the whitepapers “Mitigating Pass-the-Hash (PtH) Attacks and Other Credential Theft Techniques,” has presented the subject at Black Hat and numerous Microsoft conferences, and led the development of reference architectures to defend against this class of attacks. Mark also frequently speaks on other infrastructure security and cybersecurity topics, co-authored the whitepaper “A Systematic Method to Understand Security Risks in a Retail Environment,” and provided technical review of the whitepaper “Best Practices for Securing Active Directory.”