Use Alternate Authentication Material: Украденный билет Kerberos
Other sub-techniques of Use Alternate Authentication Material (4)
Adversaries may “pass the ticket” using stolen Kerberos tickets to move laterally within an environment, bypassing normal system access controls. Pass the ticket (PtT) is a method of authenticating to a system using Kerberos tickets without having access to an account's password. Kerberos authentication can be used as the first step to lateral movement to a remote system. When preforming PtT, valid Kerberos tickets for Valid Accounts are captured by OS Credential Dumping. A user's service tickets or ticket granting ticket (TGT) may be obtained, depending on the level of access. A service ticket allows for access to a particular resource, whereas a TGT can be used to request service tickets from the Ticket Granting Service (TGS) to access any resource the user has privileges to access.(Citation: ADSecurity AD Kerberos Attacks)(Citation: GentilKiwi Pass the Ticket) A Silver Ticket can be obtained for services that use Kerberos as an authentication mechanism and are used to generate tickets to access that particular resource and the system that hosts the resource (e.g., SharePoint).(Citation: ADSecurity AD Kerberos Attacks) A Golden Ticket can be obtained for the domain using the Key Distribution Service account KRBTGT account NTLM hash, which enables generation of TGTs for any account in Active Directory.(Citation: Campbell 2014) Adversaries may also create a valid Kerberos ticket using other user information, such as stolen password hashes or AES keys. For example, "overpassing the hash" involves using a NTLM password hash to authenticate as a user (i.e. Pass the Hash) while also using the password hash to create a valid Kerberos ticket.(Citation: Stealthbits Overpass-the-Hash)
Примеры процедур |
|
Название | Описание |
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SeaDuke |
Some SeaDuke samples have a module to use pass the ticket with Kerberos for authentication.(Citation: Symantec Seaduke 2015) |
APT29 |
APT29 used Kerberos ticket attacks for lateral movement.(Citation: Mandiant No Easy Breach) |
Mimikatz |
Mimikatz’s |
Pupy |
Pupy can also perform pass-the-ticket.(Citation: GitHub Pupy) |
APT32 |
APT32 successfully gained remote access by using pass the ticket.(Citation: Cybereason Cobalt Kitty 2017) |
BRONZE BUTLER |
BRONZE BUTLER has created forged Kerberos Ticket Granting Ticket (TGT) and Ticket Granting Service (TGS) tickets to maintain administrative access.(Citation: Secureworks BRONZE BUTLER Oct 2017) |
Контрмеры |
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Контрмера | Описание |
---|---|
Privileged Account Management |
Privileged Account Management focuses on implementing policies, controls, and tools to securely manage privileged accounts (e.g., SYSTEM, root, or administrative accounts). This includes restricting access, limiting the scope of permissions, monitoring privileged account usage, and ensuring accountability through logging and auditing.This mitigation can be implemented through the following measures: Account Permissions and Roles: - Implement RBAC and least privilege principles to allocate permissions securely. - Use tools like Active Directory Group Policies to enforce access restrictions. Credential Security: - Deploy password vaulting tools like CyberArk, HashiCorp Vault, or KeePass for secure storage and rotation of credentials. - Enforce password policies for complexity, uniqueness, and expiration using tools like Microsoft Group Policy Objects (GPO). Multi-Factor Authentication (MFA): - Enforce MFA for all privileged accounts using Duo Security, Okta, or Microsoft Azure AD MFA. Privileged Access Management (PAM): - Use PAM solutions like CyberArk, BeyondTrust, or Thycotic to manage, monitor, and audit privileged access. Auditing and Monitoring: - Integrate activity monitoring into your SIEM (e.g., Splunk or QRadar) to detect and alert on anomalous privileged account usage. Just-In-Time Access: - Deploy JIT solutions like Azure Privileged Identity Management (PIM) or configure ephemeral roles in AWS and GCP to grant time-limited elevated permissions. *Tools for Implementation* Privileged Access Management (PAM): - CyberArk, BeyondTrust, Thycotic, HashiCorp Vault. Credential Management: - Microsoft LAPS (Local Admin Password Solution), Password Safe, HashiCorp Vault, KeePass. Multi-Factor Authentication: - Duo Security, Okta, Microsoft Azure MFA, Google Authenticator. Linux Privilege Management: - sudo configuration, SELinux, AppArmor. Just-In-Time Access: - Azure Privileged Identity Management (PIM), AWS IAM Roles with session constraints, GCP Identity-Aware Proxy. |
Password Policies |
Set and enforce secure password policies for accounts to reduce the likelihood of unauthorized access. Strong password policies include enforcing password complexity, requiring regular password changes, and preventing password reuse. This mitigation can be implemented through the following measures: Windows Systems: - Use Group Policy Management Console (GPMC) to configure: - Minimum password length (e.g., 12+ characters). - Password complexity requirements. - Password history (e.g., disallow last 24 passwords). - Account lockout duration and thresholds. Linux Systems: - Configure Pluggable Authentication Modules (PAM): - Use `pam_pwquality` to enforce complexity and length requirements. - Implement `pam_tally2` or `pam_faillock` for account lockouts. - Use `pwunconv` to disable password reuse. Password Managers: - Enforce usage of enterprise password managers (e.g., Bitwarden, 1Password, LastPass) to generate and store strong passwords. Password Blacklisting: - Use tools like Have I Been Pwned password checks or NIST-based blacklist solutions to prevent users from setting compromised passwords. Regular Auditing: - Periodically audit password policies and account configurations to ensure compliance using tools like LAPS (Local Admin Password Solution) and vulnerability scanners. *Tools for Implementation* Windows: - Group Policy Management Console (GPMC): Enforce password policies. - Microsoft Local Administrator Password Solution (LAPS): Enforce random, unique admin passwords. Linux/macOS: - PAM Modules (pam_pwquality, pam_tally2, pam_faillock): Enforce password rules. - Lynis: Audit password policies and system configurations. Cross-Platform: - Password Managers (Bitwarden, 1Password, KeePass): Manage and enforce strong passwords. - Have I Been Pwned API: Prevent the use of breached passwords. - NIST SP 800-63B compliant tools: Enforce password guidelines and blacklisting. |
User Account Management |
User Account Management involves implementing and enforcing policies for the lifecycle of user accounts, including creation, modification, and deactivation. Proper account management reduces the attack surface by limiting unauthorized access, managing account privileges, and ensuring accounts are used according to organizational policies. This mitigation can be implemented through the following measures: Enforcing the Principle of Least Privilege - Implementation: Assign users only the minimum permissions required to perform their job functions. Regularly audit accounts to ensure no excess permissions are granted. - Use Case: Reduces the risk of privilege escalation by ensuring accounts cannot perform unauthorized actions. Implementing Strong Password Policies - Implementation: Enforce password complexity requirements (e.g., length, character types). Require password expiration every 90 days and disallow password reuse. - Use Case: Prevents adversaries from gaining unauthorized access through password guessing or brute force attacks. Managing Dormant and Orphaned Accounts - Implementation: Implement automated workflows to disable accounts after a set period of inactivity (e.g., 30 days). Remove orphaned accounts (e.g., accounts without an assigned owner) during regular account audits. - Use Case: Eliminates dormant accounts that could be exploited by attackers. Account Lockout Policies - Implementation: Configure account lockout thresholds (e.g., lock accounts after five failed login attempts). Set lockout durations to a minimum of 15 minutes. - Use Case: Mitigates automated attack techniques that rely on repeated login attempts. Multi-Factor Authentication (MFA) for High-Risk Accounts - Implementation: Require MFA for all administrative accounts and high-risk users. Use MFA mechanisms like hardware tokens, authenticator apps, or biometrics. - Use Case: Prevents unauthorized access, even if credentials are stolen. Restricting Interactive Logins - Implementation: Restrict interactive logins for privileged accounts to specific secure systems or management consoles. Use group policies to enforce logon restrictions. - Use Case: Protects sensitive accounts from misuse or exploitation. *Tools for Implementation* Built-in Tools: - Microsoft Active Directory (AD): Centralized account management and RBAC enforcement. - Group Policy Object (GPO): Enforce password policies, logon restrictions, and account lockout policies. Identity and Access Management (IAM) Tools: - Okta: Centralized user provisioning, MFA, and SSO integration. - Microsoft Azure Active Directory: Provides advanced account lifecycle management, role-based access, and conditional access policies. Privileged Account Management (PAM): - CyberArk, BeyondTrust, Thycotic: Manage and monitor privileged account usage, enforce session recording, and JIT access. |
Active Directory Configuration |
Implement robust Active Directory (AD) configurations using group policies to secure user accounts, control access, and minimize the attack surface. AD configurations enable centralized control over account settings, logon policies, and permissions, reducing the risk of unauthorized access and lateral movement within the network. This mitigation can be implemented through the following measures: Account Configuration: - Implementation: Use domain accounts instead of local accounts to leverage AD’s centralized management, including group policies, auditing, and access control. - Use Case: For IT staff managing shared resources, provision domain accounts that allow IT teams to log in centrally, reducing the risk of unmanaged, rogue local accounts on individual machines. Interactive Logon Restrictions: - Implementation: Configure group policies to restrict interactive logons (e.g., direct physical or RDP logons) for service accounts or privileged accounts that do not require such access. - Use Case: Prevent service accounts, such as SQL Server accounts, from having interactive logon privileges. This reduces the risk of these accounts being leveraged for lateral movement if compromised. Remote Desktop Settings: - Implementation: Limit Remote Desktop Protocol (RDP) access to specific, authorized accounts. Use group policies to enforce this, allowing only necessary users to establish RDP sessions. - Use Case: On sensitive servers (e.g., domain controllers or financial databases), restrict RDP access to administrative accounts only, while all other users are denied access. Dedicated Administrative Accounts: - Implementation: Create domain-wide administrative accounts that are restricted from interactive logons, designed solely for high-level tasks (e.g., software installation, patching). - Use Case: Create separate administrative accounts for different purposes, such as one set of accounts for installations and another for managing repository access. This limits exposure and helps reduce attack vectors. Authentication Silos: - Implementation: Configure Authentication Silos in AD, using group policies to create access zones with restrictions based on membership, such as the Protected Users security group. This restricts access to critical accounts and minimizes exposure to potential threats. - Use Case: Place high-risk or high-value accounts, such as executive or administrative accounts, in an Authentication Silo with extra controls, limiting their exposure to only necessary systems. This reduces the risk of credential misuse or abuse if these accounts are compromised. **Tools for Implementation**: - Active Directory Group Policies: Use Group Policy Management Console (GPMC) to configure, deploy, and enforce policies across AD environments. - PowerShell: Automate account configuration, logon restrictions, and policy application using PowerShell scripts. - AD Administrative Center: Manage Authentication Silos and configure high-level policies for critical user groups within AD. |
Обнаружение
Audit all Kerberos authentication and credential use events and review for discrepancies. Unusual remote authentication events that correlate with other suspicious activity (such as writing and executing binaries) may indicate malicious activity. Event ID 4769 is generated on the Domain Controller when using a golden ticket after the KRBTGT password has been reset twice, as mentioned in the mitigation section. The status code 0x1F indicates the action has failed due to "Integrity check on decrypted field failed" and indicates misuse by a previously invalidated golden ticket.(Citation: CERT-EU Golden Ticket Protection)
Ссылки
- Warren, J. (2019, February 26). How to Detect Overpass-the-Hash Attacks. Retrieved February 4, 2021.
- Metcalf, S. (2014, November 22). Mimikatz and Active Directory Kerberos Attacks. Retrieved June 2, 2016.
- Deply, B. (2014, January 13). Pass the ticket. Retrieved September 12, 2024.
- Campbell, C. (2014). The Secret Life of Krbtgt. Retrieved November 17, 2024.
- Abolins, D., Boldea, C., Socha, K., Soria-Machado, M. (2016, April 26). Kerberos Golden Ticket Protection. Retrieved July 13, 2017.
- Symantec Security Response. (2015, July 13). “Forkmeiamfamous”: Seaduke, latest weapon in the Duke armory. Retrieved July 22, 2015.
- Dunwoody, M. and Carr, N.. (2016, September 27). No Easy Breach DerbyCon 2016. Retrieved September 12, 2024.
- The Australian Cyber Security Centre (ACSC), the Canadian Centre for Cyber Security (CCCS), the New Zealand National Cyber Security Centre (NZ NCSC), CERT New Zealand, the UK National Cyber Security Centre (UK NCSC) and the US National Cybersecurity and Communications Integration Center (NCCIC). (2018, October 11). Joint report on publicly available hacking tools. Retrieved March 11, 2019.
- Schroeder, W. (2015, September 22). Mimikatz and DCSync and ExtraSids, Oh My. Retrieved December 4, 2017.
- Metcalf, S. (2015, August 7). Kerberos Golden Tickets are Now More Golden. Retrieved December 1, 2017.
- Metcalf, S. (2015, November 13). Unofficial Guide to Mimikatz & Command Reference. Retrieved December 23, 2015.
- UCF. (n.d.). The password for the krbtgt account on a domain must be reset at least every 180 days. Retrieved November 5, 2020.
- Sean Metcalf. (2014, November 10). Kerberos & KRBTGT: Active Directory’s Domain Kerberos Service Account. Retrieved January 30, 2020.
- Nicolas Verdier. (n.d.). Retrieved January 29, 2018.
- Dahan, A. (2017). Operation Cobalt Kitty. Retrieved December 27, 2018.
- Counter Threat Unit Research Team. (2017, October 12). BRONZE BUTLER Targets Japanese Enterprises. Retrieved January 4, 2018.
Связанные риски
Риск | Связи | |
---|---|---|
Обход систем защиты
из-за
возможности использования скомпрометированных билетов Kerberos
в ОС Windows
Повышение привилегий
Целостность
|
1
|
|
Боковое перемещение злоумышленника по локальной сети
из-за
возможности использования скомпрометированных билетов Kerberos
в ОС Windows
Конфиденциальность
Целостность
|
2
|
Каталоги
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