An adversary obtains (i.e. steals or purchases) legitimate Kerberos credentials (e.g. Kerberos service account userID/password or Kerberos Tickets) with the goal of achieving authenticated access to additional systems, applications, or services within the domain.

Kerberos is the default authentication method for Windows domains and is also used across many operating systems. Attacks leveraging trusted Kerberos credentials can result in numerous consequences, depending on what Kerberos credential is stolen. For example, Kerberos service accounts are typically used to run services or scheduled tasks pertaining to authentication. However, these credentials are often weak and never expire, in addition to possessing local or domain administrator privileges. If an adversary is able to acquire these credentials, it could result in lateral movement within the domain or access to any resources the service account is privileged to access, among other things. Ultimately, successful spoofing and impersonation of trusted Kerberos credentials can lead to an adversary breaking authentication, authorization, and audit controls with the target system or application.

Medium
High

1
Explore
[Acquire known Kerberos credentials] The adversary must obtain known Kerberos credentials in order to access the target system, application, or service within the domain.
An adversary purchases breached Kerberos service account username/password combinations or leaked hashed passwords from the dark web.
An adversary guesses the credentials to a weak Kerberos service account.
An adversary conducts a sniffing attack to steal Kerberos tickets as they are transmitted.
An adversary conducts a Kerberoasting attack.

2
Experiment
[Attempt Kerberos authentication] Try each Kerberos credential against various resources within the domain until the target grants access.
Manually or automatically enter each Kerberos service account credential through the target's interface.
Attempt a Pass the Ticket attack.

3
Exploit
[Impersonate] An adversary can use successful experiments or authentications to impersonate an authorized user or system, or to laterally move within the domain

4
Exploit
[Spoofing] Malicious data can be injected into the target system or into other systems on the domain. The adversary can also pose as a legitimate domain user to perform social engineering attacks.

5
Exploit
[Data Exfiltration] The adversary can obtain sensitive data contained within domain systems or applications.

The system/application leverages Kerberos authentication.
The system/application uses one factor password-based authentication, SSO, and/or cloud-based authentication for Kerberos service accounts.
The system/application does not have a sound password policy that is being enforced for Kerberos service accounts.
The system/application does not implement an effective password throttling mechanism for authenticating to Kerberos service accounts.
The targeted network allows for network sniffing attacks to succeed.

Once an adversary obtains a known Kerberos credential, leveraging it is trivial.

A valid Kerberos ticket or a known Kerberos service account credential.

Authentication attempts use expired or invalid credentials.
Authentication attempts are originating from IP addresses or locations that are inconsistent with an account's normal IP addresses or locations.
Data is being transferred and/or removed from systems/applications within the network.
Suspicious or Malicious software is downloaded/installed on systems within the domain.
Messages from a legitimate user appear to contain suspicious links or communications not consistent with the user's normal behavior.

Confidentiality
Access Control
Authentication
Gain Privileges

Confidentiality
Authorization
Read Data

Integrity
Modify Data

Create a strong password policy and ensure that your system enforces this policy for Kerberos service accounts.
Ensure Kerberos service accounts are not reusing username/password combinations for multiple systems, applications, or services.
Do not reuse Kerberos service account credentials across systems.
Deny remote use of Kerberos service account credentials to log into domain systems.
Do not allow Kerberos service accounts to be a local administrator on more than one system.
Enable at least AES Kerberos encryption for tickets.
Monitor system and domain logs for abnormal credential access.

Bronze Butler (also known as Tick), has been shown to leverage forged Kerberos Ticket Granting Tickets (TGTs) and Ticket Granting Service (TGS) tickets to maintain administrative access on a number of systems. [REF-584]
PowerSploit's Invoke-Kerberoast module can be leveraged to request Ticket Granting Service (TGS) tickets and return crackable ticket hashes. [REF-585] [REF-586]

1558
Steal or Forge Kerberos Tickets

Kerberos centers around a ticketing system that is used to request/grant access to resources and to then access the requested resources. If one of these tickets is acquired, an adversary could gain access to a specific resource; access any resource a user has privileges to access; gain access to services that use Kerberos as an authentication mechanism and generate tickets to access a particular resource and the system that hosts the resource; or generate Ticket Granting Tickets (TGTs) for any domain account within Active Directory.

CAPEC Content Team
The MITRE Corporation
2020-07-30

CAPEC Content Team
The MITRE Corporation
2020-12-17
Updated Description, Notes, Related_Attack_Patterns

CAPEC Content Team
The MITRE Corporation
2022-02-22
Updated Description, Extended_Description

CAPEC Content Team
The MITRE Corporation
2022-09-29
Updated Extended_Description, Prerequisites