The Diamond Ticket attack represents an advanced exploitation technique targeting Active Directory environments by manipulating Kerberos authentication mechanisms. This attack allows threat actors to forge Ticket Granting Tickets (TGTs) with elevated privileges while bypassing normal authentication controls. Unlike traditional Golden Ticket attacks, Diamond Tickets modify legitimate TGTs rather than creating entirely fake ones, making detection significantly more challenging for security teams.
Understanding the Diamond Ticket Attack Methodology
The Diamond Ticket attack is an evolution of Kerberos-based attacks that focuses on manipulating existing TGTs rather than creating entirely forged tickets. This technique involves obtaining the KRBTGT account’s AES hash (typically through DCSync or domain controller compromise), requesting a legitimate TGT, decrypting it, modifying the Privilege Attribute Certificate (PAC), and re-encrypting the modified TGT. Security researchers at Semperis note this approach provides greater stealth than traditional Golden Ticket attacks.
Technical Execution Requirements
To perform a Diamond Ticket attack, attackers must first obtain several critical components: the KRBTGT account’s NTLM and AES256 hashes, the domain SID (Security Identifier), and initial access to a privileged account. These requirements make the attack more sophisticated than basic credential theft but provide persistent access when successful. The attack chain typically begins with credential dumping tools like Mimikatz or Impacket’s secretsdump, as documented in The Hacker Recipes.
Detection Strategies for Security Teams
Effective detection of Diamond Ticket attacks requires monitoring specific Windows Event Logs and implementing advanced SIEM rules. Key Event IDs to monitor include 4769 (Kerberos service ticket requests), 4624 (account logons), and 4771 (Kerberos pre-authentication failures). Palo Alto Networks’ Unit 42 research recommends correlating these events with privilege escalation patterns and unusual account activity.
Comprehensive Mitigation Approaches
Organizations should implement multiple defensive layers against Diamond Ticket attacks. Critical measures include regular KRBTGT account password rotation (twice to invalidate cached tickets), disabling legacy encryption protocols like RC4-HMAC, and enforcing least privilege principles. Splunk’s threat research team emphasizes the importance of enabling detailed Kerberos logging (Event IDs 4768-4771) and implementing PAC validation for all services.
Strategic Implications for Security Professionals
For red teams, the Diamond Ticket technique provides a stealthier alternative to Golden Ticket attacks during adversary simulations. Blue teams should focus on detecting unusual Kerberos ticket requests and monitoring KRBTGT account access patterns. As noted in detection engineering research, understanding both the attack methodology and defensive strategies is crucial for comprehensive Active Directory protection.
Conclusion and Security Recommendations
The Diamond Ticket attack demonstrates the continued evolution of Kerberos exploitation techniques in enterprise environments. Organizations should prioritize regular credential rotation, comprehensive logging, and strict access controls to mitigate this advanced threat. Continuous monitoring for authentication anomalies and implementing defensive best practices remains essential for maintaining Active Directory security against sophisticated attacks.
