LSASS stands for Local Security Authority Subsystem Service, a crucial Windows process (lsass.exe) responsible for enforcing security policies, handling user logins, and managing password changes. It stores sensitive credential information in memory, such as user names and password hashes. Because of this, LSASS is a frequent target for attackers seeking to extract credentials using tools like Mimikatz. Gaining access to LSASS memory can allow attackers to move laterally within a network or escalate privileges. Protecting LSASS is vital for maintaining system and network security, and best practices include enabling Credential Guard, restricting access, and monitoring for suspicious activity.