Trusted Relationship
- ID
- T1199
- Tactics
- TA0001 Initial Access
- Platforms
- IaaS, Identity Provider, Linux, macOS, Office Suite, SaaS, Windows
- Data sources
- Logon Session Creation, Logon Session Metadata, Network Connection Creation, Application Log Content, Network Traffic Content
- Source
- attack.mitre.org
- MITRE last modified
- 12 May 2026
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.[3]
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.[4]
Detection
- DET0488 Detect abuse of Trusted Relationships (third-party and delegated admin access)
Data components: Logon Session Creation, Logon Session Metadata, Network Connection Creation, Application Log Content, Network Traffic Content
Mitigations (3)
- M1018 User Account Management
Properly manage accounts and permissions used by parties in trusted relationships to minimize potential abuse by the party and if the party is compromised by an adversary. In Office 365 environments, partner relationships and roles can be viewed under the “Partner Relationships” page.[1]
- M1030 Network Segmentation
Network segmentation can be used to isolate infrastructure components that do not require broad network access.
- M1032 Multi-factor Authentication
Require MFA for all delegated administrator accounts.[2]
Groups (14)
- G0007 APT28
- G0016 APT29
- G0027 Threat Group-3390
- G0034 Sandworm Team
- G0045 menuPass
- G0115 GOLD SOUTHFIELD
- G0125 HAFNIUM
- G1004 LAPSUS$
- G1005 POLONIUM
- G1039 RedCurl
- G1041 Sea Turtle
- G1045 Salt Typhoon
- G1055 VOID MANTICORE
- G1059 NIMBUS MANTICORE
References
- Office 365 Partner Relationships
- Microsoft Nobelium Admin Privileges
- CISA IT Service Providers
- Office 365 Delegated Administration
