Golden Ticket Attacks: How to Detect. A Golden Ticket attack is a malicious cybersecurity attack where a threat actor tries to access user data stored in Microsoft Active Directory (AD) to obtain nearly unrestricted access to an organization’s domain (files, devices, domain controllers, etc.). It circumvents standard authentication by using flaws in the Kerberos identity authentication protocol, which attackers utilize to gain access to the AD.
As organizations increasingly rely on robust security measures, understanding the anatomy of these attacks becomes paramount. In this article, we delve into the mechanics of Golden Ticket attacks, shedding light on the techniques employed by attackers and providing actionable insights on effective detection methods to safeguard against this sophisticated security breach.
Golden Ticket Attacks: How Attackers Forge Tickets & How to Detect
Employees already use their own devices and networks to log into company systems, expanding the attack surface beyond the traditional perimeter as businesses move toward the cloud and a remote-first approach. In turn, it has increased the risk of attackers breaking into a network and using a Golden Ticket attack to gain access.
History of the Golden Ticket Attack
The term “Golden Ticket” in cybersecurity, inspired by Roald Dahl’s “Charlie and the Chocolate Factory,” symbolizes a coveted pass. Much like the novel’s golden ticket granting access to Willy Wonka’s exclusive world, a “Golden Ticket” in cybersecurity refers to a forged Kerberos ticket, offering unauthorized access.
Here’s a brief historical overview:
- Development of Mimikatz:
- Benjamin Delpy created Mimikatz to demonstrate and address security weaknesses in Windows authentication protocols.
- The tool gained attention for its ability to extract plaintext passwords, Kerberos tickets, and other sensitive information from memory.
2. Golden Ticket Concept:
- “Golden Ticket” refers to a forged Kerberos ticket granting unauthorized, persistent network access.
- An attacker can impersonate any user and access network resources using a Golden Ticket made with Mimikatz or similar tools. All without requiring the user’s credentials.
3. Advanced Persistent Threats (APTs):
- APT groups, known for their sophisticated and persistent nature, started incorporating the Golden Ticket technique into their attack strategies.
- The technique allows attackers to maintain long-term access to a compromised network, making it challenging for defenders to detect and mitigate the threat.
4. Mitigations and Defenses:
- As awareness of the Golden Ticket attack increased, organizations and cybersecurity professionals focused on implementing mitigations.
- Best practices include regular monitoring of Active Directory for unusual activity, enforcing the principle of least privilege, and keeping systems and software up to date.
Mitigations involve heightened awareness and security measures. Organizations emphasize Active Directory monitoring, enforcing the principle of least privilege, and maintaining up-to-date systems to counter the Golden Ticket attack. This technique exemplifies the continual cat-and-mouse game in cybersecurity, emphasizing the need for innovative security measures to outpace evolving threats.
Golden Ticket Attack Process
A key distribution center is typically used in Kerberos authentication to safeguard and confirm user identification. Using Kerberos authentication, it is unnecessary to ask the user for credentials repeatedly. Instead, we confirm the user’s identity and issue a ticket to them for access. The Distribution center has a ticket-granting server (TGS) to connect the user to the service server.
The Kerberos database contains the passwords of all verified users. The authentication server (AS) performs the user’s initial authentication. If AS is confirmed, the user gets a Kerberos Ticket Grant Ticket (TGT), proof of authentication.
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How Attackers Perform Golden Ticket Attacks
An attacker needs the fully qualified domain name, domain security identifier, the hash of the KRBTGT password. and the username of the account to access and conduct a Golden Ticket assault. The following procedures explain how an attacker obtains this data and how to launch the attack.
Step 1: Examine – The initial phase, the attacker needs existing system access, often achieved through phishing emails. These deceptive emails are the entry point, allowing attackers to scrutinize and gather essential information such as the domain name.
Step 2: Acquire Access – Following successful entry to the domain controller, the attacker pilers the NTLM hash of the AD Key Distribution Service Account (KRBTGT). Techniques like Pass-the-Hash (PtH) are employed, offering an advantage by eliminating the need for password cracking, unlike other credential theft methods.
Step 3: Initiate Assault – Armed with the KRBTGT password, the attacker obtains a Ticket Granting Ticket (TGT), facilitating access to the domain controller and verifying the server’s identity. TGTs endow the attacker with unfettered access to resources, enabling them to delegate domain-related tasks and generate tickets.
Step 4. Retain Access – The ticket is valid for up to 10 years, and this attack is often undetected. Generally, attackers set the keys to be valid for a shorter period to escape detection further.
Detecting Golden Ticket Attacks
Organizations should implement several procedures to help them identify potential Golden Ticket attacks. Once an attacker has completed Step 2 and acquired access, they get login credentials for subsequent attacks. Attackers utilized automated technologies with previously uncovered staff and customer data to locate active accounts.
Depending on whether the login credentials are valid, Kerberos sends different responses when it receives a TGT request without first authenticating. Attackers take advantage of this and use legitimate credentials in potential attacks in the future. Security teams might search for several tickets from a single source without pre-authentication.
Using Extended Detection and Response (XDR)
Extended Detection and Response (XDR) adopts a holistic perspective on security operations. It assimilates and analyses data from diverse sources within an organization’s IT infrastructure, encompassing endpoints, networks, and cloud platforms.
Threat data is gathered by XDR systems from many tools inside an organization’s technology stack, facilitating a faster threat-hunting and response procedure. With integrated threat data from across the technological stack, XDR solutions may combine all detection and responses into a single command console, allowing an organization to identify a Golden Ticket attack more quickly.
Tips to Prevent Golden Ticket Attacks
Golden Ticket attacks require a compromised environment because they are post-exploitation attacks. The following guidelines assist in preventing access by intruders.
Tip 1: Secure Active Directory
Safeguarding Active Directory (AD) is paramount as a compromised endpoint or workload significantly threatens the entire enterprise. Implementing Zero Trust principles, emphasizing continuous verification and authorization, protects AD and user identities. Apply the principle of least privilege (POLP), which improves AD security by allocating access privileges based on job activities. It is imperative to maintain visibility into user access.
Tip 2: Prioritize the Prevention of Credential Theft
Focus on preventing credential theft, a common precursor outlined in Step 1 of the attack process. Staff training to identify and thwart phishing attempts is essential to block attackers’ initial access. Employing IT hygiene tools is instrumental in maintaining the security of credentials, ensuring their safety, and enforcing password changes. This proactive approach enhances the likelihood of detecting and thwarting Golden Ticket attacks on compromised systems.
Tip 3: Embrace Threat Hunting
Human-led threat hunting plays a crucial role in identifying and countering stealthy attacks utilizing stolen credentials, especially in the case of a Golden Ticket attack that may elude automated security tools. Threat hunting involves skilled professionals operating under the guise of legitimate users to uncover subtle threats. Leveraging expertise gained from daily encounters with advanced persistent threat (APT) actors, threat-hunting teams scrutinize millions of potential threats daily, distinguishing between legitimate and malicious leads and issuing alerts when necessary.
Golden Ticket Attacks: How to Detect Conclusion
As the digital realm continues to confront a barrage of cyber threats, the menace of Golden Ticket attacks underscores the importance of proactive defense strategies. Vigilance against the artful exploitation of authentication vulnerabilities is not merely a choice but a necessity in safeguarding sensitive networks. By staying ahead of the curve with robust detection mechanisms, organizations fortify their cyber defences and mitigate the risks posed by these covert infiltrations, ensuring a resilient and secure digital future.
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