T1199: Trusted Relationship
Adversaries may breach or otherwise leverage organizations who have access to intended victims. Access through trusted third party relationship abuses an existing connection that may not be protected or receives less scrutiny than standard mechanisms of gaining access to a network.
Organizations often grant elevated access to second or third-party external providers in order to allow them to manage internal systems as well as cloud-based environments. Some examples of these relationships include IT services contractors, managed security providers, infrastructure contractors (e.g. HVAC, elevators, physical security). The third-party provider's access may be intended to be limited to the infrastructure being maintained, but may exist on the same network as the rest of the enterprise. As such, Valid Accounts used by the other party for access to internal network systems may be compromised and used.
In Office 365 environments, organizations may grant Microsoft partners or resellers delegated administrator permissions. By compromising a partner or reseller account, an adversary may be able to leverage existing delegated administrator relationships or send new delegated administrator offers to clients in order to gain administrative control over the victim tenant.
How it's found
Detect abuse of Trusted Relationships (third-party and delegated admin access): Behavioral chain: (1) a login from a third-party account or untrusted source network establishes an interactive/remote session; (2) the session acquires elevated privileges or accesses sensitive resources atypical for that account; (3) subsequent lateral movement or data access occurs from the same session/device. Correlate Windows logon events, token elevation/privileged use, and resource access with third-party context. Behavioral chain: (1) sshd or federated SSO logins from third-party networks or identities; (2) rapid sudo/su privilege elevation; (3) access to sensitive paths or east-west SSH. Correlate auth logs, process execution, and network flows. Behavioral chain: (1) third-party interactive login or mobileconfig-based device enrollment; (2) privilege use or admin group change; (3) lateral movement mounts/ssh. Correlate unified logs and network telemetry. Behavioral chain: (1) delegated admin or external identity establishes session (e.g., partner/reseller DAP, B2B guest, SAML/OAuth trust); (2) role elevation or app consent/permission grant; (3) downstream privileged actions in the tenant. Correlate IdP sign-in, admin/role assignment, and consent/admin-on-behalf events. Behavioral chain: (1) cross-account or third-party principal assumes a role into the tenant/subscription/project; (2) privileged API calls are made in short succession; (3) access originates from unfamiliar networks or geos. Correlate assume-role/federation events with sensitive API usage. Behavioral chain: (1) third-party app or admin connects via OAuth/marketplace install; (2) high-privilege scopes granted; (3) anomalous actions (mass read/exports, admin changes). Behavioral chain: (1) delegated administration offers/relationships created or modified by partner tenants; (2) mailbox delegation/impersonation enabled; (3) follow-on access from partner IPs.
Standards mapping
Where this fits in a TurboPentest engagement
This weakness is not covered by the automated black-box pentest. IntegSec pentesters cover it in a manual engagement.
Frequently asked questions
What is T1199 Trusted Relationship?
Adversaries may breach or otherwise leverage organizations who have access to intended victims. Access through trusted third party relationship abuses an existing connection that may not be protected or receives less scrutiny than standard mechanisms of gaining access to a network. Organizations often grant elevated access to second or third-party external providers in order to allow them to manage internal systems as well as cloud-based environments. Some examples of these relationships include IT services contractors, managed security providers, infrastructure contractors (e.g. HVAC, elevators, physical security). The third-party provider's access may be intended to be limited to the infrastructure being maintained, but may exist on the same network as the rest of the enterprise. As such, Valid Accounts used by the other party for access to internal network systems may be compromised and used. In Office 365 environments, organizations may grant Microsoft partners or resellers delegated administrator permissions. By compromising a partner or reseller account, an adversary may be able to leverage existing delegated administrator relationships or send new delegated administrator offers to clients in order to gain administrative control over the victim tenant.
Which tactics does T1199 belong to?
T1199 maps to the Initial Access tactic.
Does TurboPentest test for Trusted Relationship?
This weakness is not covered by the automated black-box pentest. IntegSec pentesters cover it in a manual engagement.
Related MITRE ATT&CK techniques
- Initial Access, Persistence, Privilege Escalation, StealthT1078: Valid Accounts
- Initial Access, Lateral MovementT1091: Replication Through Removable Media
- Initial Access, PersistenceT1133: External Remote Services
- Initial AccessT1189: Drive-by Compromise
- Initial AccessT1190: Exploit Public-Facing Application
- Initial AccessT1195: Supply Chain Compromise
About this reference
These security references are maintained by IntegSec, an offensive-security firm whose team holds CISSP, OSCP, and OSCE certifications and has run thousands of penetration tests. Content is kept current as tools, standards, and attack techniques evolve.
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