Active Directory remains the backbone of identity management for most enterprises, making it a prime target for attackers. Modern attack techniques like Kerberoasting, Pass-the-Hash, and DCSync can compromise an entire domain if Active Directory is not properly secured and monitored.
Hardening Active Directory
Tiered administration is the foundation of AD security. Administrative accounts should be separated into tiers: Tier 0 for domain controllers and AD management, Tier 1 for server administration, and Tier 2 for workstation management. Administrators should never use Tier 0 credentials from lower-tier systems, preventing credential theft through compromised workstations.
Privileged Access Workstations provide hardened, dedicated systems for administrative tasks. These workstations run minimal software, enforce application whitelisting, and are isolated from general network traffic. Combined with just-in-time privilege elevation through tools like Microsoft's Privileged Identity Management, they significantly reduce the window of opportunity for credential theft.
Continuous monitoring of AD security events is essential. Alerting on DCSync operations, unusual Kerberos ticket requests, changes to sensitive groups, and modifications to Group Policy Objects provides early warning of compromise attempts. Purple team exercises that simulate AD attack chains help validate that detection capabilities are effective.