Techniques › T1199
T1199 Trusted Relationship
initial access — IaaS, Identity Provider, Linux, macOS, Office Suite, SaaS, Windows · attack.mitre.org · JSON
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MITRE detection strategy
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analytics
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Sigma rules tagged attack.t1199
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KEV CVEs mapped here
<p>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.</p><p>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.</p><p>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.</p>
KEV CVEs mapped to this technique · CTID Mappings Explorer
| CVE | Vendor / product | Mapping type | State | Added |
|---|---|---|---|---|
| CVE-2024-53704 | SonicWall SonicOS | exploitation technique | Mapped | 2025-02-18 |
Detection strategy · ATT&CK Enterprise v19.2
- DET0488 Detect abuse of Trusted Relationships (third-party and delegated admin access) v1.0
AN1344 WindowsBehavioral 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.Tunable:
ThirdPartyCIDRsExpectedAdminHostsTimeWindowHighValueResourcesAN1345 LinuxBehavioral 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.Tunable:ThirdPartyUsersAllowedJumpHostsMFAExpectedAN1346 macOSBehavioral 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.NSM:Flowssh/smb connections to internal resources from third-party devices→ DC0085 Network Traffic ContentTunable:ManagedDeviceListAN1347 Identity ProviderBehavioral 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.azure:auditAdd delegated admin / Assign admin roles / Update application consent→ DC0088 Logon Session Metadatam365:unifiedSet-PartnerOfRecord / CompanyAdministrator role assignments / New-DelegatedAdminRelationship→ DC0038 Application Log ContentTunable:TrustedPartnerTenantIDsRequiredMFARoleScopeAllowListAN1348 IaaSBehavioral 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.AWS:CloudTrailAssumeRole,AssumeRoleWithSAML,AssumeRoleWithWebIdentity→ DC0067 Logon Session CreationAWS:CloudTrailCreateUser|AttachRolePolicy|CreateAccessKey|UpdateAssumeRolePolicy|CreateLoginProfile→ DC0038 Application Log Contentgcp:auditgoogle.iam.credentials.generateAccessToken / serviceAccountTokenCreator→ DC0088 Logon Session MetadataTunable:ExternalAccountAllowListSensitiveAPIsGeoVelocityThresholdAN1349 SaaSBehavioral 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).saas:googleworkspaceOAuth2 authorization grants / Admin role assignments→ DC0038 Application Log ContentTunable:ApprovedAppsExportVolumeThresholdAN1350 Office SuiteBehavioral chain: (1) delegated administration offers/relationships created or modified by partner tenants; (2) mailbox delegation/impersonation enabled; (3) follow-on access from partner IPs.m365:unifiedAdd-DelegatedAdmin, Set-PartnerOfRecord, Add-MailboxPermission, Set-OrganizationRelationship→ DC0038 Application Log ContentTunable:MailboxDelegateAllowList
Sigma rules · SigmaHQ da9bb07d64, tag attack.t1199
Author: zendannyy
· 2026-04-28 · logsource: product=okta service=okta · fe04b26b-0ac4-45d7-9404-4b9f16a440a9
Detects Okta session impersonation grant event where a user is granted the ability to impersonate another user's session.
This event type "user.session.impersonation.grant" signifies that someone has been given temporary access to act on behalf of another user account.
Threat actors may abuse this functionality to escalate privileges, access sensitive resources, or perform unauthorized actions while appearing to be the impersonated user.
Legitimate use cases are typically limited to Okta support scenarios or authorized administrative troubleshooting.
Author: austinsonger
· 2021-08-19 (modified 2022-10-09) · logsource: product=m365 service=threat_management · ff246f56-7f24-402a-baca-b86540e3925c
Detects when a Security Compliance Center reported a user who exceeded sending limits of the service policies and because of this has been restricted from sending email.