CTD-000078

Stale Microsoft Entra guest account

Informational
Entra ID
Credential Access Persistence
v28

Signature Identity

CTD-000078
Threat ID
28
Version
IOE
Indicator Type

Threat Description

As users collaborate with external partners, it’s possible that many guest accounts get created in Microsoft Entra tenants over time. When collaboration ends and the users no longer access your tenant, the guest accounts may become stale. Threat actors might compromise these guest accounts and use them to access your tenant.

MITRE ATT&CK: Attack Tactics

Credential Access Persistence

D3FEND: Defend Tactics

Domain Account Monitoring

Remediation

To delete a user, follow these steps:

  1. Sign in to the Microsoft Entra admin center.
  2. Go to Identity > Users > All users.
  3. Search for and select the user you want to delete from your Microsoft Entra tenant.
  4. Select Delete user.

Frequently Asked Questions

What does Stale Microsoft Entra guest account mean?

A stale Microsoft Entra guest account is an inactive guest user that remains in the tenant after collaboration with external partners has ended. These accounts can be used by attackers to collect information about users and groups within the tenant.

Stale Microsoft Entra guest account is rated as informational because it indicates exposure, but does not prove active compromise. An attacker can use a stale guest account to collect information about the tenant, which increases the risk of future attacks.

Attackers can use a stale Microsoft Entra guest account to gather reconnaissance data in your Entra ID tenant by collecting information about users and groups. This information helps them plan more targeted intrusions, including identifying potential entry points for future attacks.

Cayosoft Guardian detects stale Microsoft Entra guest accounts through continuous monitoring of the tenant for inactive guest users. When a stale guest account is found, Guardian flags it as a security issue so administrators can review and delete unnecessary users.

Cayosoft Guardian helps reduce the risk of stale Microsoft Entra guest accounts by alerting administrators to delete inactive users. This limits the reconnaissance opportunities available to attackers and keeps the tenant free from unnecessary access points, ultimately reducing the attack surface.

Stop AD Threats As They Happen

Cayosoft Protector provides continuous monitoring and real-time alerts across your entire Microsoft Identity stack

Classification
Systems
Entra ID
Themes
Account protection Guest management
Attack Tactics
Credential Access Persistence
Defend Tactics
Domain Account Monitoring
Indicator Types
IOE
Related Threats
CTD-000139
Kerberos Constrained Delegation: krbtgt Risks
Critical
CTD-000122
Active Directory Schema Update Permission Risks
Critical