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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.1

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.2

Item Value
ID T1199
Tactics TA0001
Platforms IaaS, Linux, Office 365, SaaS, Windows, macOS
Version 2.3
Created 18 April 2018
Last Modified 21 October 2022

Procedure Examples

ID Name Description
G0007 APT28 Once APT28 gained access to the DCCC network, the group then proceeded to use that access to compromise the DNC network.15
G0016 APT29 APT29 has compromised IT, cloud services, and managed services providers to gain broad access to multiple customers for subsequent operations.16
G0115 GOLD SOUTHFIELD GOLD SOUTHFIELD has breached Managed Service Providers (MSP’s) to deliver malware to MSP customers.6
G1004 LAPSUS$ LAPSUS$ has accessed internet-facing identity providers such as Azure Active Directory and Okta to target specific organizations.5
G0045 menuPass menuPass has used legitimate access granted to Managed Service Providers in order to access victims of interest.109111213
G1005 POLONIUM POLONIUM has used compromised credentials from an IT company to target downstream customers including a law firm and aviation company.8
G0034 Sandworm Team Sandworm Team has used dedicated network connections from one victim organization to gain unauthorized access to a separate organization.14
C0024 SolarWinds Compromise During the SolarWinds Compromise, APT29 gained access through compromised accounts at cloud solution partners, and used compromised certificates issued by Mimecast to authenticate to Mimecast customer systems.1817
G0027 Threat Group-3390 Threat Group-3390 has compromised third party service providers to gain access to victim’s environments.7


ID Mitigation Description
M1032 Multi-factor Authentication Require MFA for all delegated administrator accounts.3
M1030 Network Segmentation Network segmentation can be used to isolate infrastructure components that do not require broad network access.
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.4


ID Data Source Data Component
DS0015 Application Log Application Log Content
DS0028 Logon Session Logon Session Creation
DS0029 Network Traffic Network Traffic Content


  1. CISA. (n.d.). APTs Targeting IT Service Provider Customers. Retrieved November 16, 2020. 

  2. Microsoft. (n.d.). Partners: Offer delegated administration. Retrieved May 27, 2022. 

  3. Microsoft Threat Intelligence Center. (2021, October 25). NOBELIUM targeting delegated administrative privileges to facilitate broader attacks. Retrieved January 31, 2022. 

  4. Microsoft. (2022, March 4). Manage partner relationships. Retrieved May 27, 2022. 

  5. MSTIC, DART, M365 Defender. (2022, March 24). DEV-0537 Criminal Actor Targeting Organizations for Data Exfiltration and Destruction. Retrieved May 17, 2022. 

  6. Counter Threat Unit Research Team. (2019, September 24). REvil/Sodinokibi Ransomware. Retrieved August 4, 2020. 

  7. Global Threat Center, Intelligence Team. (2020, December). APT27 Turns to Ransomware. Retrieved November 12, 2021. 

  8. Microsoft. (2022, June 2). Exposing POLONIUM activity and infrastructure targeting Israeli organizations. Retrieved July 1, 2022. 

  9. FireEye iSIGHT Intelligence. (2017, April 6). APT10 (MenuPass Group): New Tools, Global Campaign Latest Manifestation of Longstanding Threat. Retrieved June 29, 2017. 

  10. PwC and BAE Systems. (2017, April). Operation Cloud Hopper: Technical Annex. Retrieved April 13, 2017. 

  11. Symantec. (2020, November 17). Japan-Linked Organizations Targeted in Long-Running and Sophisticated Attack Campaign. Retrieved December 17, 2020. 

  12. United States District Court Southern District of New York (USDC SDNY) . (2018, December 17). United States of America v. Zhu Hua and Zhang Shilong. Retrieved April 17, 2019. 

  13. US District Court Southern District of New York. (2018, December 17). United States v. Zhu Hua Indictment. Retrieved December 17, 2020. 

  14. Scott W. Brady. (2020, October 15). United States vs. Yuriy Sergeyevich Andrienko et al.. Retrieved November 25, 2020. 

  15. Mueller, R. (2018, July 13). Indictment - United States of America vs. VIKTOR BORISOVICH NETYKSHO, et al. Retrieved September 13, 2018. 

  16. Microsoft Threat Intelligence Center. (2021, October 25). NOBELIUM targeting delegated administrative privileges to facilitate broader attacks. Retrieved March 25, 2022. 

  17. CrowdStrike. (2022, January 27). Early Bird Catches the Wormhole: Observations from the StellarParticle Campaign. Retrieved February 7, 2022. 

  18. NCSC, CISA, FBI, NSA. (2021, May 7). Further TTPs associated with SVR cyber actors. Retrieved July 29, 2021.