Entra ID User Sign-in with Unusual Non-Managed Device
Description
Identifies when a Microsoft Entra ID user signs in from a device that is not typically used by the user and is not managed, which may indicate potential compromise or unauthorized access attempts. This rule detects unusual sign-in activity by comparing the device used for the sign-in against the user's typical device usage patterns. Adversaries may create and register a new device to obtain a Primary Refresh Token (PRT) and maintain persistent access.
Query · kuery
data_stream.dataset: "azure.signinlogs" and
event.category: "authentication" and
azure.signinlogs.properties.user_type: "Member" and
azure.signinlogs.properties.token_protection_status_details.sign_in_session_status: "unbound" and
not azure.signinlogs.properties.device_detail.is_managed: true and
not azure.signinlogs.properties.device_detail.device_id: "" and
not azure.signinlogs.properties.device_detail.trust_type: "Hybrid Azure AD joined" and
not (azure.signinlogs.category: "NonInteractiveUserSignInLogs" and azure.signinlogs.properties.incoming_token_type: "none") and
azure.signinlogs.properties.user_principal_name: *
Investigation fields
Pivot points the source recommends for triage.
azure.signinlogs.properties.user_principal_nameazure.signinlogs.properties.device_detail.device_idazure.signinlogs.properties.incoming_token_typeazure.signinlogs.categorysource.geo.country_namesource.geo.city_namesource.addressazure.signinlogs.properties.app_idazure.signinlogs.properties.resource_idazure.signinlogs.properties.risk_levelazure.signinlogs.properties.risk_detail
Implementation guide
This rule requires the Azure integration with Microsoft Entra ID Sign-In logs to be enabled and configured to collect audit and activity logs via Azure Event Hub.
Analyst notes
Investigating Entra ID User Sign-in with Unusual Non-Managed Device
This rule detects when a Microsoft Entra ID user signs in from a device that is not typically used by the user, which may indicate potential compromise or unauthorized access attempts. This rule detects unusual sign-in activity by comparing the device used for the sign-in against the user's typical device usage patterns. Adversaries may create and register a new device to obtain a Primary Refresh Token (PRT) and maintain persistent access.
Possible investigation steps
- Review the
azure.signinlogs.properties.user_principal_namefield to identify the user associated with the sign-in. - Check the
azure.signinlogs.properties.device_detail.device_idfield to identify the device used for the sign-in. - Review
azure.signinlogs.properties.incoming_token_typeto determine what tpe of security token was used for the sign-in, such as a Primary Refresh Token (PRT). - Examine
azure.signinlogs.categoryto determine if these were non-interactive or interactive sign-ins. - Check the geolocation of the sign-in by reviewing
source.geo.country_nameandsource.geo.city_nameto identify the location of the device used for the sign-in. If these are unusual for the user, it may indicate a potential compromise. - Review
azure.signinlogs.properties.app_idto determine which client application was used for the sign-in. If the application is not recognized or expected, it may indicate unauthorized access. Adversaries use first-party client IDs to blend in with legitimate traffic. - Examine
azure.signinlogs.properties.resource_idto determine what resource the security token has in scope and/or is requesting access to. If the resource is not recognized or expected, it may indicate unauthorized access. Excessive access to Graph API is common post-compromise behavior. - Review the identity protection risk status by checking
azure.signinlogs.properties.risk_levelandazure.signinlogs.properties.risk_detailto determine if the sign-in was flagged as risky by Entra ID Protection.
False positive analysis
- Legitimate users may sign in from new devices, such as when using a new laptop or mobile device. If this is expected behavior, consider adjusting the rule or adding exceptions for specific users or device IDs.
- Environments where users frequently change devices, such as in a corporate setting with rotating hardware, may generate false positives.
- Users may use both an endpoint and mobile device for sign-ins, which could trigger this rule.
- Hybrid Azure AD joined devices often report
is_managed: falsewhen Intune MDM is not enrolled; that corporate hybrid-join state is excluded. Azure AD joined devices are kept in scope because OAuth phishing / ROADtx device registration commonly creates cloud-joined (not hybrid) unmanaged devices. - Non-interactive sign-ins with
azure.signinlogs.properties.incoming_token_typeof"none"(common Microsoft first-party background token acquisition on registered devices) are excluded;"primaryRefreshToken"(PRT) and"refreshToken"activity remain in scope.
Response and remediation
- If the sign-in is confirmed to be suspicious or unauthorized, take immediate action to revoke the access token and prevent further access.
- Disable the user account temporarily to prevent any potential compromise or unauthorized access.
- Review the user's recent sign-in activity and access patterns to identify any potential compromise or unauthorized access.
- If the user account is compromised, initiate a password reset and enforce multi-factor authentication (MFA) for the user.
- Review the conditional access policies in place to ensure they are sufficient to prevent unauthorized access to sensitive resources.
- Identify the registered Entra ID device by reviewing
azure.signinlogs.properties.device_detail.display_nameand confirm it is expected for the user or organization. If it is not expected, consider removing the device registration. - Consider adding exceptions for verified devices that are known to be used by the user to reduce false-positives.