Entra ID User Sign-in with Unusual Non-Managed Device

  1[metadata]
  2creation_date = "2025/06/16"
  3integration = ["azure"]
  4maturity = "production"
  5updated_date = "2026/08/12"
  6
  7[rule]
  8author = ["Elastic"]
  9description = """
 10Identifies 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
 11indicate potential compromise or unauthorized access attempts. This rule detects unusual sign-in activity by comparing
 12the device used for the sign-in against the user's typical device usage patterns. Adversaries may create and register a
 13new device to obtain a Primary Refresh Token (PRT) and maintain persistent access.
 14"""
 15from = "now-9m"
 16index = ["filebeat-*", "logs-azure.signinlogs-*"]
 17language = "kuery"
 18license = "Elastic License v2"
 19name = "Entra ID User Sign-in with Unusual Non-Managed Device"
 20note = """## Triage and analysis
 21
 22### Investigating Entra ID User Sign-in with Unusual Non-Managed Device
 23
 24This 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.
 25
 26### Possible investigation steps
 27- Review the `azure.signinlogs.properties.user_principal_name` field to identify the user associated with the sign-in.
 28- Check the `azure.signinlogs.properties.device_detail.device_id` field to identify the device used for the sign-in.
 29- Review `azure.signinlogs.properties.incoming_token_type` to determine what tpe of security token was used for the sign-in, such as a Primary Refresh Token (PRT).
 30- Examine `azure.signinlogs.category` to determine if these were non-interactive or interactive sign-ins.
 31- Check the geolocation of the sign-in by reviewing `source.geo.country_name` and `source.geo.city_name` to identify the location of the device used for the sign-in. If these are unusual for the user, it may indicate a potential compromise.
 32- Review `azure.signinlogs.properties.app_id` to 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.
 33- Examine `azure.signinlogs.properties.resource_id` to 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.
 34- Review the identity protection risk status by checking `azure.signinlogs.properties.risk_level` and `azure.signinlogs.properties.risk_detail` to determine if the sign-in was flagged as risky by Entra ID Protection.
 35
 36### False positive analysis
 37- 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.
 38- Environments where users frequently change devices, such as in a corporate setting with rotating hardware, may generate false positives.
 39- Users may use both an endpoint and mobile device for sign-ins, which could trigger this rule.
 40- Hybrid Azure AD joined devices often report `is_managed: false` when 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.
 41- Non-interactive sign-ins with `azure.signinlogs.properties.incoming_token_type` of `"none"` (common Microsoft first-party background token acquisition on registered devices) are excluded; `"primaryRefreshToken"` (PRT) and `"refreshToken"` activity remain in scope.
 42
 43### Response and remediation
 44- If the sign-in is confirmed to be suspicious or unauthorized, take immediate action to revoke the access token and prevent further access.
 45- Disable the user account temporarily to prevent any potential compromise or unauthorized access.
 46- Review the user's recent sign-in activity and access patterns to identify any potential compromise or unauthorized access.
 47- If the user account is compromised, initiate a password reset and enforce multi-factor authentication (MFA) for the user.
 48- Review the conditional access policies in place to ensure they are sufficient to prevent unauthorized access to sensitive resources.
 49- Identify the registered Entra ID device by reviewing `azure.signinlogs.properties.device_detail.display_name` and confirm it is expected for the user or organization. If it is not expected, consider removing the device registration.
 50- Consider adding exceptions for verified devices that are known to be used by the user to reduce false-positives.
 51"""
 52references = [
 53    "https://pushsecurity.com/blog/consentfix",
 54    "https://www.volexity.com/blog/2025/04/22/phishing-for-codes-russian-threat-actors-target-microsoft-365-oauth-workflows/",
 55    "https://dirkjanm.io/phishing-for-microsoft-entra-primary-refresh-tokens/",
 56]
 57risk_score = 21
 58rule_id = "72c91fc0-4ac0-11f0-811f-f661ea17fbcd"
 59setup = """#### Required Microsoft Entra ID Sign-In Logs
 60This 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.
 61"""
 62severity = "low"
 63tags = [
 64    "Domain: Cloud",
 65    "Domain: Identity",
 66    "Use Case: Threat Detection",
 67    "Tactic: Persistence",
 68    "Data Source: Azure",
 69    "Data Source: Microsoft Entra ID",
 70    "Data Source: Microsoft Entra ID Sign-in Logs",
 71    "Platform: Entra ID",
 72    "Resources: Investigation Guide",
 73
 74]
 75timestamp_override = "event.ingested"
 76type = "new_terms"
 77
 78query = '''
 79data_stream.dataset: "azure.signinlogs" and
 80    event.category: "authentication" and
 81    azure.signinlogs.properties.user_type: "Member" and
 82    azure.signinlogs.properties.token_protection_status_details.sign_in_session_status: "unbound" and
 83    not azure.signinlogs.properties.device_detail.is_managed: true and
 84    not azure.signinlogs.properties.device_detail.device_id: "" and
 85    not azure.signinlogs.properties.device_detail.trust_type: "Hybrid Azure AD joined" and
 86    not (azure.signinlogs.category: "NonInteractiveUserSignInLogs" and azure.signinlogs.properties.incoming_token_type: "none") and
 87    azure.signinlogs.properties.user_principal_name: *
 88'''
 89
 90
 91[[rule.threat]]
 92framework = "MITRE ATT&CK"
 93
 94[[rule.threat.technique]]
 95id = "T1098"
 96name = "Account Manipulation"
 97reference = "https://attack.mitre.org/techniques/T1098/"
 98
 99[[rule.threat.technique.subtechnique]]
100id = "T1098.005"
101name = "Device Registration"
102reference = "https://attack.mitre.org/techniques/T1098/005/"
103
104[rule.threat.tactic]
105id = "TA0003"
106name = "Persistence"
107reference = "https://attack.mitre.org/tactics/TA0003/"
108
109[[rule.threat]]
110framework = "MITRE ATT&CK"
111
112[[rule.threat.technique]]
113id = "T1078"
114name = "Valid Accounts"
115reference = "https://attack.mitre.org/techniques/T1078/"
116
117[[rule.threat.technique.subtechnique]]
118id = "T1078.004"
119name = "Cloud Accounts"
120reference = "https://attack.mitre.org/techniques/T1078/004/"
121
122[rule.threat.tactic]
123id = "TA0001"
124name = "Initial Access"
125reference = "https://attack.mitre.org/tactics/TA0001/"
126
127[rule.investigation_fields]
128field_names = [
129    "azure.signinlogs.properties.user_principal_name",
130    "azure.signinlogs.properties.device_detail.device_id",
131    "azure.signinlogs.properties.incoming_token_type",
132    "azure.signinlogs.category",
133    "source.geo.country_name",
134    "source.geo.city_name",
135    "source.address",
136    "azure.signinlogs.properties.app_id",
137    "azure.signinlogs.properties.resource_id",
138    "azure.signinlogs.properties.risk_level",
139    "azure.signinlogs.properties.risk_detail",
140]
141
142[rule.new_terms]
143field = "new_terms_fields"
144value = [
145    "azure.signinlogs.properties.user_principal_name",
146    "azure.signinlogs.properties.device_detail.device_id",
147]
148[[rule.new_terms.history_window_start]]
149field = "history_window_start"
150value = "now-7d"