Azure AD User Consent Denied for OAuth Application

name: Azure AD User Consent Denied for OAuth Application
id: bb093c30-d860-4858-a56e-cd0895d5b49c
version: 14
creation_date: '2023-11-16'
modification_date: '2026-05-13'
author: Mauricio Velazco, Splunk
status: production
type: TTP
description: The following analytic identifies instances where a user has denied consent to an OAuth application seeking permissions within the Azure AD environment. This detection leverages Azure AD's audit logs, specifically focusing on user consent actions with error code 65004. Monitoring denied consent actions is significant as it can indicate users recognizing potentially suspicious or untrusted applications. If confirmed malicious, this activity could suggest attempts by unauthorized applications to gain access, potentially leading to data breaches or unauthorized actions within the environment. Understanding these denials helps refine security policies and enhance user awareness.
data_source:
    - Azure Active Directory Sign-in activity
search: |-
    `azure_monitor_aad` operationName="Sign-in activity" properties.status.errorCode=65004
      | rename properties.* as *
      | fillnull
      | stats count min(_time) as firstTime max(_time) as lastTime
        BY dest user src
           vendor_account vendor_product appDisplayName
           status.failureReason signature
      | `security_content_ctime(firstTime)`
      | `security_content_ctime(lastTime)`
      | `azure_ad_user_consent_denied_for_oauth_application_filter`
how_to_implement: You must install the latest version of Splunk Add-on for Microsoft Cloud Services from Splunkbase (https://splunkbase.splunk.com/app/3110/#/details). You must be ingesting Azure Active Directory events into your Splunk environment through an EventHub. This analytic was written to be used with the azure:monitor:aad sourcetype leveraging the SignInLogs log category.
known_false_positives: Users may deny consent for legitimate applications by mistake, filter as needed.
references:
    - https://attack.mitre.org/techniques/T1528/
    - https://www.microsoft.com/en-us/security/blog/2022/09/22/malicious-oauth-applications-used-to-compromise-email-servers-and-spread-spam/
    - https://learn.microsoft.com/en-us/azure/active-directory/manage-apps/protect-against-consent-phishing
    - https://learn.microsoft.com/en-us/defender-cloud-apps/investigate-risky-oauth
    - https://www.alteredsecurity.com/post/introduction-to-365-stealer
    - https://github.com/AlteredSecurity/365-Stealer
drilldown_searches:
    - name: View the detection results for - "$user$"
      search: '%original_detection_search% | search  user = "$user$"'
      earliest_offset: $info_min_time$
      latest_offset: $info_max_time$
    - name: View risk events for the last 7 days for - "$user$"
      search: '| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$user$") | stats count min(_time) as firstTime max(_time) as lastTime values(search_name) as "Search Name" values(risk_message) as "Risk Message" values(analyticstories) as "Analytic Stories" values(annotations._all) as "Annotations" values(annotations.mitre_attack.mitre_tactic) as "ATT&CK Tactics" by normalized_risk_object | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)`'
      earliest_offset: 7d
      latest_offset: "0"
finding:
    title: User $user$ denied consent for an OAuth application.
    entity:
        field: user
        type: user
        score: 50
analytic_story:
    - Azure Active Directory Account Takeover
asset_type: Azure Tenant
mitre_attack_id:
    - T1528
product:
    - Splunk Enterprise
    - Splunk Enterprise Security
    - Splunk Cloud
category: cloud
security_domain: identity
tests:
    - name: True Positive Test
      attack_data:
        - data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1528/azure_ad_user_consent_declined/azure_ad_user_consent_declined.log
          source: Azure AD
          sourcetype: azure:monitor:aad
      test_type: unit