CTD-000057

AD forest with the Azure SSO computer account not changing its password

High
Active Directory Entra ID Hybrid
Credential Access
v27

Signature Identity

CTD-000057
Threat ID
27
Version
IOC
Indicator Type

Threat Description

Microsoft Entra Seamless Single Sign-On (Microsoft Entra Seamless SSO) automatically signs users in when they are on their corporate devices connected to your corporate network. When enabled, users don’t need to type in their passwords to sign in to Microsoft Entra ID, and usually, even type in their usernames. This feature provides your users easy access to your cloud-based applications without needing any additional on-premises components. A special computer account AZUREADSSOACC is used to provide Microsoft Entra Seamless SSO functionality. If a threat actor can compromise password of AZUREADSSOACC, then the threat actor could generate a Ticket Granting Service (TGS) request to the AZUREADSSOACC account as any user. With the ticket received threat actor can impersonate a user in Microsoft Entra ID. The password of the AZUREADSSOACC account never changes, so the stolen hash/key will work forever unless password is changed. This security flaw could be misused by highly privileged employees to retain access to the environment after leaving the company.

MITRE ATT&CK: Attack Tactics

Credential Access

D3FEND: Defend Tactics

Domain Account Monitoring

Remediation

To update the Kerberos decryption key:

  1. Download and install Azure Active Directory PowerShell for Graph.
  2. Navigate to the %ProgramFiles%\Microsoft Entra Connect folder.
  3. Import the Seamless SSO PowerShell module using this command Import-Module .\AzureADSSO.psd1.
  4. Run PowerShell as an Administrator.
  5. In PowerShell, call New-AzureADSSOAuthenticationContext. This command should give you a popup to enter your tenant’s Global Administrator or Hybrid Identity Administrator credentials.
  6. Call $creds = Get-Credential.
  7. When prompted, enter the Domain Administrator credentials for the intended AD forest.
  8. Call Update-AzureADSSOForest -OnPremCredentials $creds. This command updates the Kerberos decryption key for the AZUREADSSO computer account in this specific AD forest and updates it in Microsoft Entra ID.

Frequently Asked Questions

What does AD forest with the Azure SSO computer account not changing its password mean?

The AZUREADSSOACC account has a static password that never changes, allowing an attacker who knows the password to authenticate as any user with access to Microsoft Entra ID.

This vulnerability allows attackers to gain access to sensitive resources and escalate privileges, making it a significant security risk. An attacker who knows the AZUREADSSOACC account's password can authenticate as any user with access to Microsoft Entra ID.

Attackers can exploit this vulnerability by using the static AZUREADSSOACC account password to authenticate as any user with access to Microsoft Entra ID, granting them access to sensitive data or administrative tasks.

Cayosoft Guardian continuously monitors the state of the AZUREADSSOACC account's password and flags it as a security issue when a static or unchanged password is detected, providing visibility to administrators.

Cayosoft Guardian alerts administrators to update the Kerberos decryption key for the AZUREADSSOACC account, ensuring that the password is changed and the vulnerability is mitigated. This prevents attackers from using the static password to authenticate as any user with access to Microsoft Entra ID.

Stop AD Threats As They Happen

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Classification
Systems
Active Directory Entra ID Hybrid
Themes
Forest-wide Tenant-wide
Attack Tactics
Credential Access
Defend Tactics
Domain Account Monitoring
Indicator Types
IOC
Related Threats
CTD-000139
Kerberos Constrained Delegation: krbtgt Risks
Critical
CTD-000122
Active Directory Schema Update Permission Risks
Critical