Golden Ticket Attacks: Exploiting Kerberos to Compromise Active Directory Security

Kerberos Golden Ticket Attack

A Golden Ticket attack is a powerful, stealthy cyberattack targeting Windows Active Directory environments. It exploits the Kerberos authentication protocol to grant attackers virtually unlimited access to an organization's domain resources, including devices, files, and domain controllers. Here's a detailed breakdown:

1. What is a Golden Ticket Attack?

A Golden Ticket attack involves forging a Kerberos Ticket Granting Ticket (TGT) using the password hash of the KRBTGT account. The KRBTGT account is a special account in Active Directory responsible for encrypting and signing all Kerberos tickets. By compromising this account, attackers can create fake TGTs that appear legitimate, granting them unrestricted access to the domain.

2. How a Golden Ticket Attack Works

• Initial Compromise: The attacker gains administrative access to the domain controller, often through other attacks like credential dumping or privilege escalation.
• Extracting the KRBTGT Hash: Using tools like Mimikatz, the attacker extracts the NTLM hash of the KRBTGT account.
• Forging the Golden Ticket: The attacker uses the KRBTGT hash, along with the domain name and Security Identifier (SID), to create a forged TGT.
• Using the Golden Ticket: The attacker loads the forged TGT into memory, allowing them to impersonate any user, including domain administrators, and access any resource in the domain.

3. Why Golden Ticket Attacks are Dangerous

• Persistence: Golden Tickets remain valid until the KRBTGT password is reset twice, which is rarely done due to operational challenges.
• Stealth: The attack uses legitimate Kerberos tickets, making it difficult to detect.
• Unlimited Access: Attackers can impersonate any user and access sensitive resources without triggering alarms.

4. Mitigation Strategies

• Regularly Reset KRBTGT Password: Resetting the KRBTGT password twice invalidates existing Golden Tickets.
• Monitor for Anomalies: Use security tools to detect unusual Kerberos ticket activity.
• Limit Privileges: Minimize the number of accounts with domain admin privileges.
• Implement Multi-Factor Authentication (MFA): Add an extra layer of security to critical accounts.
• Use Endpoint Detection and Response (EDR) Tools: Detect and respond to suspicious activity on endpoints.

5. Tools Used in Golden Ticket Attacks

Mimikatz: A popular tool for extracting credentials and forging Kerberos tickets.

Impacket: A Python library for crafting network protocols, including Kerberos tickets.

Rubeus: A tool for Kerberos ticket manipulation and attacks.

Golden Ticket attacks are a significant threat to Active Directory environments, but with proactive security measures, organizations can reduce their risk.