Suspicious modification of Global Administrator user properties

Hunt Hypothesis

An adversary may be attempting to modify Global Administrator user properties to escalate privileges or maintain persistence within the environment. SOC teams should proactively hunt for this behavior in Azure Sentinel to identify potential insider threats or unauthorized access attempts.

KQL Query

let query_frequency = 1h;
let query_period = 14d;
IdentityInfo
| where TimeGenerated > ago(query_period)
| where set_has_element(AssignedRoles, "Global Administrator")
| distinct AccountUPN, AccountObjectId
| join kind=inner (
    AuditLogs
    | where TimeGenerated > ago(query_frequency)
    | where OperationName=~ "Update user" and Result =~ "success"
    // | where isnotempty(InitiatedBy["user"])
    | mv-expand TargetResource = TargetResources
    | where TargetResource["type"] == "User"
    | extend AccountObjectId = tostring(TargetResource["id"])
    | where tostring(TargetResource["modifiedProperties"]) != "[]"
    | mv-apply modifiedProperty = TargetResource["modifiedProperties"] on (
        summarize modifiedProperties = make_bag(
            bag_pack(tostring(modifiedProperty["displayName"]),
                bag_pack("oldValue", trim(@'[\"\s]+', tostring(modifiedProperty["oldValue"])),
                    "newValue", trim(@'[\"\s]+', tostring(modifiedProperty["newValue"])))))
    )
    | where not(tostring(modifiedProperties["Included Updated Properties"]["newValue"]) in ("LastDirSyncTime", ""))
    | where not(tostring(modifiedProperties["Included Updated Properties"]["newValue"]) == "StrongAuthenticationPhoneAppDetail" and isnotempty(modifiedProperties["StrongAuthenticationPhoneAppDetail"]) and tostring(array_sort_asc(extract_all(@'\"Id\"\:\"([^\"]+)\"', tostring(modifiedProperties["StrongAuthenticationPhoneAppDetail"]["newValue"])))) == tostring(array_sort_asc(extract_all(@'\"Id\"\:\"([^\"]+)\"', tostring(modifiedProperties["StrongAuthenticationPhoneAppDetail"]["oldValue"])))))
    | extend
        Initiator = iif(isnotempty(InitiatedBy["app"]), tostring(InitiatedBy["app"]["displayName"]), tostring(InitiatedBy["user"]["userPrincipalName"])),
        InitiatorId = iif(isnotempty(InitiatedBy["app"]), tostring(InitiatedBy["app"]["servicePrincipalId"]), tostring(InitiatedBy["user"]["id"])),
        IPAddress = tostring(InitiatedBy[tostring(bag_keys(InitiatedBy)[0])]["ipAddress"])
) on AccountObjectId
| project TimeGenerated, Category, Identity, Initiator, IPAddress, OperationName, Result, AccountUPN, InitiatedBy, AdditionalDetails, TargetResources, AccountObjectId, InitiatorId, CorrelationId
| extend
    InitiatorName = tostring(split(Initiator, "@")[0]),
    InitiatorUPNSuffix = tostring(split(Initiator, "@")[1]),
    AccountName = tostring(split(AccountUPN, "@")[0]),
    AccountUPNSuffix = tostring(split(AccountUPN, "@")[1])

Analytic Rule Definition

id: 48602a24-67cf-4362-b258-3f4249e55def
name: Suspicious modification of Global Administrator user properties
description: |
  'This query will detect if user properties of Global Administrator are updated by an existing user. Usually only user administrator or other global administrator can update such properties.
  Investigate if such user change is an attempt to elevate an existing low privileged identity or rogue administrator activity'
severity: Medium
requiredDataConnectors:
  - connectorId: AzureActiveDirectory
    dataTypes:
      - AuditLogs
  - connectorId: BehaviorAnalytics
    dataTypes:
      - IdentityInfo
queryFrequency: 1h
queryPeriod: 14d
triggerOperator: gt
triggerThreshold: 0
tactics:
  - PrivilegeEscalation
relevantTechniques:
  - T1078.004
query: |
  let query_frequency = 1h;
  let query_period = 14d;
  IdentityInfo
  | where TimeGenerated > ago(query_period)
  | where set_has_element(AssignedRoles, "Global Administrator")
  | distinct AccountUPN, AccountObjectId
  | join kind=inner (
      AuditLogs
      | where TimeGenerated > ago(query_frequency)
      | where OperationName=~ "Update user" and Result =~ "success"
      // | where isnotempty(InitiatedBy["user"])
      | mv-expand TargetResource = TargetResources
      | where TargetResource["type"] == "User"
      | extend AccountObjectId = tostring(TargetResource["id"])
      | where tostring(TargetResource["modifiedProperties"]) != "[]"
      | mv-apply modifiedProperty = TargetResource["modifiedProperties"] on (
          summarize modifiedProperties = make_bag(
              bag_pack(tostring(modifiedProperty["displayName"]),
                  bag_pack("oldValue", trim(@'[\"\s]+', tostring(modifiedProperty["oldValue"])),
                      "newValue", trim(@'[\"\s]+', tostring(modifiedProperty["newValue"])))))
      )
      | where not(tostring(modifiedProperties["Included Updated Properties"]["newValue"]) in ("LastDirSyncTime", ""))
      | where not(tostring(modifiedProperties["Included Updated Properties"]["newValue"]) == "StrongAuthenticationPhoneAppDetail" and isnotempty(modifiedProperties["StrongAuthenticationPhoneAppDetail"]) and tostring(array_sort_asc(extract_all(@'\"Id\"\:\"([^\"]+)\"', tostring(modifiedProperties["StrongAuthenticationPhoneAppDetail"]["newValue"])))) == tostring(array_sort_asc(extract_all(@'\"Id\"\:\"([^\"]+)\"', tostring(modifiedProperties["StrongAuthenticationPhoneAppDetail"]["oldValue"])))))
      | extend
          Initiator = iif(isnotempty(InitiatedBy["app"]), tostring(InitiatedBy["app"]["displayName"]), tostring(InitiatedBy["user"]["userPrincipalName"])),
          InitiatorId = iif(isnotempty(InitiatedBy["app"]), tostring(InitiatedBy["app"]["servicePrincipalId"]), tostring(InitiatedBy["user"]["id"])),
          IPAddress = tostring(InitiatedBy[tostring(bag_keys(InitiatedBy)[0])]["ipAddress"])
  ) on AccountObjectId
  | project TimeGenerated, Category, Identity, Initiator, IPAddress, OperationName, Result, AccountUPN, InitiatedBy, 

Required Data Sources

MITRE ATT&CK Context

• Tactic: PrivilegeEscalation
• Technique: T1078.004 — T1078.004

References

• Source Query

False Positive Guidance

• Scenario: Scheduled Job Updates User Properties
  Description: A scheduled job or automation tool (e.g., Azure Automation, PowerShell scripts, or third-party identity management tools) updates the properties of a Global Administrator user as part of routine maintenance or configuration.
  Filter/Exclusion: Exclude activity related to known automation tools or scheduled tasks by checking the caller or source field for entries like Azure Automation, PowerShell, or specific job names.

• Scenario: User Self-Service Portal Updates
  Description: A Global Administrator user modifies their own properties (e.g., email, password, or display name) via the Microsoft 365 Admin Center or Azure AD portal.
  Filter/Exclusion: Exclude users who are also Global Administrators by checking the user_principal_name or user_type field for entries like user_admin or Global Administrator.

• Scenario: Multi-Factor Authentication (MFA) Configuration Changes
  Description: An admin modifies MFA settings for a Global Administrator user (e.g., enabling or disabling MFA, changing authentication methods) via the Azure AD portal or Intune.
  Filter/Exclusion: Exclude changes related to MFA by checking the operation_name or change_type field for entries like MFA configuration, authentication method, or multi-factor authentication.

• Scenario: User Profile Synchronization with On-Premises AD
  Description: A Global Administrator user’s properties are updated via user profile synchronization between on-premises Active Directory and Azure AD (e.g., using Azure AD Connect).
  Filter/Exclusion: Exclude synchronization events by checking the source or change_source field for entries like Azure AD Connect, on-premises AD, or sync.

• Scenario: User Property Changes via API or Third-Party Tool