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  1. Frameworks
  2. >ATTACK
  3. >Initial Access
  4. >ATTACK-T1199
ATTACK-T1199Active

Trusted Relationship

Statement

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.(Citation: CISA IT Service Providers)

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.(Citation: Office 365 Delegated Administration)

Location

Tactic
Initial Access

Technique Details

Identifier
ATTACK-T1199
ATT&CK Page
View on MITRE

Tactics

Initial Access

Platforms

WindowsSaaSIaaSLinuxmacOSIdentity ProviderOffice Suite

Detection

Detect abuse of Trusted Relationships (third-party and delegated admin access)

Mitigations

Multi-factor Authentication: Multi-Factor Authentication (MFA) enhances security by requiring users to provide at least two forms of verification to prove their identity before granting access. These factors typically include:

  • Something you know: Passwords, PINs.
  • Something you have: Physical tokens, smartphone authenticator apps.
  • Something you are: Biometric data such as fingerprints, facial recognition, or retinal scans.

Implementing MFA across all critical systems and services ensures robust protection against account takeover and unauthorized access. This mitigation can be implemented through the following measures:

Identity and Access Management (IAM):

  • Use IAM solutions like Azure Active Directory, Okta, or AWS IAM to enforce MFA policies for all user logins, especially for privileged roles.
  • Enable conditional access policies to enforce MFA for risky sign-ins (e.g., unfamiliar devices, geolocations).
  • Enable Conditional Access policies to only allow logins from trusted devices, such as those enrolled in Intune or joined via Hybrid/Entra.

Authentication Tools and Methods:

  • Use authenticator applications such as Google Authenticator, Microsoft Authenticator, or Authy for time-based one-time passwords (TOTP).
  • Deploy hardware-based tokens like YubiKey, RSA SecurID, or smart cards for additional security.
  • Enforce biometric authentication for compatible devices and applications.

Secure Legacy Systems:

  • Integrate MFA solutions with older systems using third-party tools like Duo Security or Thales SafeNet.
  • Enable RADIUS/NPS servers to facilitate MFA for VPNs, RDP, and other network logins.

Monitoring and Alerting:

  • Use SIEM tools to monitor failed MFA attempts, login anomalies, or brute-force attempts against MFA systems.
  • Implement alerts for suspicious MFA activities, such as repeated failed codes or new device registrations.

Training and Policy Enforcement:

  • Educate employees on the importance of MFA and secure authenticator usage.
  • Enforce policies that require MFA on all critical systems, especially for remote access, privileged accounts, and cloud applications.

User Account Management: User Account Management involves implementing and enforcing policies for the lifecycle of user accounts, including creation, modification, and deactivation. Proper account management reduces the attack surface by limiting unauthorized access, managing account privileges, and ensuring accounts are used according to organizational policies. This mitigation can be implemented through the following measures:

Enforcing the Principle of Least Privilege

  • Implementation: Assign users only the minimum permissions required to perform their job functions. Regularly audit accounts to ensure no excess permissions are granted.
  • Use Case: Reduces the risk of privilege escalation by ensuring accounts cannot perform unauthorized actions.

Implementing Strong Password Policies

  • Implementation: Enforce password complexity requirements (e.g., length, character types). Require password expiration every 90 days and disallow password reuse.
  • Use Case: Prevents adversaries from gaining unauthorized access through password guessing or brute force attacks.

Managing Dormant and Orphaned Accounts

  • Implementation: Implement automated workflows to disable accounts after a set period of inactivity (e.g., 30 days). Remove orphaned accounts (e.g., accounts without an assigned owner) during regular account audits.
  • Use Case: Eliminates dormant accounts that could be exploited by attackers.

Account Lockout Policies

  • Implementation: Configure account lockout thresholds (e.g., lock accounts after five failed login attempts). Set lockout durations to a minimum of 15 minutes.
  • Use Case: Mitigates automated attack techniques that rely on repeated login attempts.

Multi-Factor Authentication (MFA) for High-Risk Accounts

  • Implementation: Require MFA for all administrative accounts and high-risk users. Use MFA mechanisms like hardware tokens, authenticator apps, or biometrics.
  • Use Case: Prevents unauthorized access, even if credentials are stolen.

Restricting Interactive Logins

  • Implementation: Restrict interactive logins for privileged accounts to specific secure systems or management consoles. Use group policies to enforce logon restrictions.
  • Use Case: Protects sensitive accounts from misuse or exploitation.

Tools for Implementation

Built-in Tools:

  • Microsoft Active Directory (AD): Centralized account management and RBAC enforcement.
  • Group Policy Object (GPO): Enforce password policies, logon restrictions, and account lockout policies.

Identity and Access Management (IAM) Tools:

  • Okta: Centralized user provisioning, MFA, and SSO integration.
  • Microsoft Azure Active Directory: Provides advanced account lifecycle management, role-based access, and conditional access policies.

Privileged Account Management (PAM):

  • CyberArk, BeyondTrust, Thycotic: Manage and monitor privileged account usage, enforce session recording, and JIT access.

Network Segmentation: Network segmentation involves dividing a network into smaller, isolated segments to control and limit the flow of traffic between devices, systems, and applications. By segmenting networks, organizations can reduce the attack surface, restrict lateral movement by adversaries, and protect critical assets from compromise.

Effective network segmentation leverages a combination of physical boundaries, logical separation through VLANs, and access control policies enforced by network appliances like firewalls, routers, and cloud-based configurations. This mitigation can be implemented through the following measures:

Segment Critical Systems:

  • Identify and group systems based on their function, sensitivity, and risk. Examples include payment systems, HR databases, production systems, and internet-facing servers.
  • Use VLANs, firewalls, or routers to enforce logical separation.

Implement DMZ for Public-Facing Services:

  • Host web servers, DNS servers, and email servers in a DMZ to limit their access to internal systems.
  • Apply strict firewall rules to filter traffic between the DMZ and internal networks.

Use Cloud-Based Segmentation:

  • In cloud environments, use VPCs, subnets, and security groups to isolate applications and enforce traffic rules.
  • Apply AWS Transit Gateway or Azure VNet peering for controlled connectivity between cloud segments.

Apply Microsegmentation for Workloads:

  • Use software-defined networking (SDN) tools to implement workload-level segmentation and prevent lateral movement.

Restrict Traffic with ACLs and Firewalls:

  • Apply Access Control Lists (ACLs) to network devices to enforce "deny by default" policies.
  • Use firewalls to restrict both north-south (external-internal) and east-west (internal-internal) traffic.

Monitor and Audit Segmented Networks:

  • Regularly review firewall rules, ACLs, and segmentation policies.
  • Monitor network flows for anomalies to ensure segmentation is effective.

Test Segmentation Effectiveness:

  • Perform periodic penetration tests to verify that unauthorized access is blocked between network segments.
SP 800-53
SP800-53-AC-3relatedvia ctid-attack-to-sp800-53
SP800-53-AC-4relatedvia ctid-attack-to-sp800-53
SP800-53-AC-6relatedvia ctid-attack-to-sp800-53
SP800-53-AC-8relatedvia ctid-attack-to-sp800-53
SP800-53-CM-6relatedvia ctid-attack-to-sp800-53
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Initial Access15 controls
ATTACK-T1189Drive-by CompromiseATTACK-T1190Exploit Public-Facing ApplicationATTACK-T1195Supply Chain CompromiseATTACK-T1195.001Compromise Software Dependencies and Development ToolsATTACK-T1195.002Compromise Software Supply ChainATTACK-T1195.003Compromise Hardware Supply ChainATTACK-T1199Trusted RelationshipATTACK-T1200Hardware AdditionsATTACK-T1566PhishingATTACK-T1566.001Spearphishing AttachmentATTACK-T1566.002Spearphishing LinkATTACK-T1566.003Spearphishing via ServiceATTACK-T1566.004Spearphishing VoiceATTACK-T1659Content InjectionATTACK-T1669Wi-Fi Networks