Adversaries may add new domain trusts, modify the properties of existing domain trusts, or otherwise change the configuration of trust relationships between domains and tenants to evade defenses and/or elevate privileges.Trust details, such as whether or not user identities are federated, allow authentication and authorization properties to apply between domains or tenants for the purpose of accessing shared resources.(Citation: Microsoft - Azure AD Federation) These trust objects may include accounts, credentials, and other authentication material applied to servers, tokens, and domains.

Manipulating these trusts may allow an adversary to escalate privileges and/or evade defenses by modifying settings to add objects which they control. For example, in Microsoft Active Directory (AD) environments, this may be used to forge [SAML Tokens](https://attack.mitre.org/techniques/T1606/002) without the need to compromise the signing certificate to forge new credentials. Instead, an adversary can manipulate domain trusts to add their own signing certificate. An adversary may also convert an AD domain to a federated domain using Active Directory Federation Services (AD FS), which may enable malicious trust modifications such as altering the claim issuance rules to log in any valid set of credentials as a specified user.(Citation: AADInternals zure AD Federated Domain) 

An adversary may also add a new federated identity provider to an identity tenant such as Okta, which may enable the adversary to authenticate as any user of the tenant.(Citation: Okta Cross-Tenant Impersonation 2023)
Trust Modification
source_name: mitre-attack  url: https://attack.mitre.org/techniques/T1484/002  external_id: T1484.002     source_name: CISA SolarWinds Cloud Detection  description: CISA. (2021, January 8). Detecting Post-Compromise Threat Activity in Microsoft Cloud Environments. Retrieved January 8, 2021.  url: https://us-cert.cisa.gov/ncas/alerts/aa21-008a     source_name: AADInternals zure AD Federated Domain  description: Dr. Nestori Syynimaa. (2017, November 16). Security vulnerability in Azure AD & Office 365 identity federation. Retrieved September 28, 2022.  url: https://o365blog.com/post/federation-vulnerability/     source_name: Microsoft - Azure AD Federation  description: Microsoft. (2018, November 28). What is federation with Azure AD?. Retrieved December 30, 2020.  url: https://docs.microsoft.com/en-us/azure/active-directory/hybrid/whatis-fed     source_name: Microsoft - Azure Sentinel ADFSDomainTrustMods  description: Microsoft. (2020, December). Azure Sentinel Detections. Retrieved December 30, 2020.  url: https://github.com/Azure/Azure-Sentinel/blob/master/Detections/AuditLogs/ADFSDomainTrustMods.yaml     source_name: Microsoft - Update or Repair Federated domain  description: Microsoft. (2020, September 14). Update or repair the settings of a federated domain in Office 365, Azure, or Intune. Retrieved December 30, 2020.  url: https://docs.microsoft.com/en-us/office365/troubleshoot/active-directory/update-federated-domain-office-365     source_name: Okta Cross-Tenant Impersonation 2023  description: Okta Defensive Cyber Operations. (2023, August 31). Cross-Tenant Impersonation: Prevention and Detection. Retrieved February 15, 2024.  url: https://sec.okta.com/articles/2023/08/cross-tenant-impersonation-prevention-and-detection     source_name: Sygnia Golden SAML  description: Sygnia. (2020, December). Detection and Hunting of Golden SAML Attack. Retrieved January 6, 2021.  url: https://www.sygnia.co/golden-saml-advisory     