Adversaries may register a device to an adversary-controlled account. Devices may be registered in a multifactor authentication (MFA) system, which handles authentication to the network, or in a device management system, which handles device access and compliance.
MFA systems, such as Duo or Okta, allow users to associate devices with their accounts in order to complete MFA requirements. An adversary that compromises a user’s credentials may enroll a new device in order to bypass initial MFA requirements and gain persistent access to a network.[1][2] In some cases, the MFA self-enrollment process may require only a username and password to enroll the account's first device or to enroll a device to an inactive account. [3]
Similarly, an adversary with existing access to a network may register a device or a virtual machine to Entra ID and/or its device management system, Microsoft Intune, in order to access sensitive data or resources while bypassing conditional access policies.[4][5][6][7]
Devices registered in Entra ID may be able to conduct Internal Spearphishing campaigns via intra-organizational emails, which are less likely to be treated as suspicious by the email client.[8] Additionally, an adversary may be able to perform a Service Exhaustion Flood on an Entra ID tenant by registering a large number of devices.[9]
| ID | Name | Description |
|---|---|---|
| S0677 | AADInternals |
AADInternals can register a device to Azure AD.[10] |
| G0016 | APT29 |
APT29 has enrolled their own devices into compromised cloud tenants, including enrolling a device in MFA to an Azure AD environment following a successful password guessing attack against a dormant account.[3][11] |
| C0027 | C0027 |
During C0027, Scattered Spider registered devices for MFA to maintain persistence through victims' VPN.[12] |
| C0024 | SolarWinds Compromise |
During the SolarWinds Compromise, APT29 registered devices in order to enable mailbox syncing via the |
| ID | Mitigation | Description |
|---|---|---|
| M1032 | Multi-factor Authentication |
Require multi-factor authentication to register devices in Entra ID.[8] Configure multi-factor authentication systems to disallow enrolling new devices for inactive accounts.[1] When first enrolling MFA, use conditional access policies to restrict device enrollment to trusted locations or devices, and consider using temporary access passes as an initial MFA solution to enroll a device.[3] |
| ID | Name | Analytic ID | Analytic Description |
|---|---|---|---|
| DET0036 | Suspicious Device Registration via Entra ID or MFA Platform | AN0103 |
Adversary registers new devices to compromised user accounts to bypass MFA or conditional access policies via Azure Entra ID, Okta, or Duo self-enrollment portals. |
| AN0104 |
Adversary registers a Windows device to Entra ID or bypasses conditional access by adding device via Intune registration pipeline using stolen credentials. |