Detection rules › Splunk

O365 Block User Consent For Risky Apps Disabled

Status
production
Severity
medium
Group by
AllowUserConsentForRiskyApps, aws::recipientAccountId, dest, signature, src, user, vendor_product
Author
Mauricio Velazco, Splunk
Source
github.com/splunk/security_content

The following analytic detects when the "risk-based step-up consent" security setting in Microsoft 365 is disabled. It monitors Azure Active Directory logs for the "Update authorization policy" operation, specifically changes to the "AllowUserConsentForRiskyApps" setting. This activity is significant because disabling this feature can expose the organization to OAuth phishing threats, allowing users to grant consent to malicious applications. If confirmed malicious, attackers could gain unauthorized access to user data and sensitive information, leading to data breaches and further compromise within the organization.

MITRE ATT&CK coverage

TacticTechniques
Defense ImpairmentT1685 Disable or Modify Tools

Rule body splunk

name: O365 Block User Consent For Risky Apps Disabled
id: 12a23592-e3da-4344-8545-205d3290647c
version: 10
creation_date: '2023-12-06'
modification_date: '2026-05-13'
author: Mauricio Velazco, Splunk
status: production
type: TTP
description: The following analytic detects when the "risk-based step-up consent" security setting in Microsoft 365 is disabled. It monitors Azure Active Directory logs for the "Update authorization policy" operation, specifically changes to the "AllowUserConsentForRiskyApps" setting. This activity is significant because disabling this feature can expose the organization to OAuth phishing threats, allowing users to grant consent to malicious applications. If confirmed malicious, attackers could gain unauthorized access to user data and sensitive information, leading to data breaches and further compromise within the organization.
data_source:
    - O365 Update authorization policy.
search: "`o365_management_activity` Workload=AzureActiveDirectory Operation=\"Update authorization policy.\" | eval index_number = if(mvfind('ModifiedProperties{}.Name',\"AllowUserConsentForRiskyApps\") >= 0, mvfind('ModifiedProperties{}.Name',\"AllowUserConsentForRiskyApps\"), -1) | search index_number >= 0 | eval AllowUserConsentForRiskyApps = mvindex('ModifiedProperties{}.NewValue',index_number) | where AllowUserConsentForRiskyApps like \"%true%\" | fillnull | stats count min(_time) as firstTime max(_time) as lastTime by signature dest user src vendor_account vendor_product AllowUserConsentForRiskyApps | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)` | `o365_block_user_consent_for_risky_apps_disabled_filter`"
how_to_implement: You must install the Splunk Microsoft Office 365 Add-on and ingest Office 365 management activity events.
known_false_positives: Legitimate changes to the 'risk-based step-up consent' setting by administrators, perhaps as part of a policy update or security assessment, may trigger this alert, necessitating verification of the change's intent and authorization.
references:
    - https://attack.mitre.org/techniques/T1562/
    - https://goodworkaround.com/2020/10/19/a-look-behind-the-azure-ad-permission-classifications-preview/
    - https://learn.microsoft.com/en-us/entra/identity/enterprise-apps/configure-risk-based-step-up-consent
    - https://learn.microsoft.com/en-us/defender-cloud-apps/investigate-risky-oauth
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: Risk-based step-up consent security setting was disabled by $user$
    entity:
        field: user
        type: user
        score: 50
analytic_story:
    - Office 365 Account Takeover
asset_type: O365 Tenant
mitre_attack_id:
    - T1685
product:
    - Splunk Enterprise
    - Splunk Enterprise Security
    - Splunk Cloud
category: cloud
security_domain: audit
tests:
    - name: True Positive Test
      attack_data:
        - data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1562/o365_disable_blockconsent_for_riskapps/o365_disable_blockconsent_for_riskapps.log
          source: O365
          sourcetype: o365:management:activity
      test_type: unit

Stages and Predicates

Stage 1: search

`o365_management_activity` Workload=AzureActiveDirectory Operation="Update authorization policy."

Stage 2: eval

| eval index_number = if(mvfind('ModifiedProperties{}.Name',"AllowUserConsentForRiskyApps") >= 0, mvfind('ModifiedProperties{}.Name',"AllowUserConsentForRiskyApps"), -1)

Stage 3: search

| search index_number >= 0

Stage 4: eval

| eval AllowUserConsentForRiskyApps = mvindex('ModifiedProperties{}.NewValue',index_number)

Stage 5: where

| where AllowUserConsentForRiskyApps like "%true%"

Stage 6: fillnull

| fillnull

Stage 7: stats

| stats count min(_time) as firstTime max(_time) as lastTime by signature dest user src vendor_account vendor_product AllowUserConsentForRiskyApps

Stage 8: search

| `security_content_ctime(firstTime)`

Stage 9: search

| `security_content_ctime(lastTime)`

Stage 10: search

| `o365_block_user_consent_for_risky_apps_disabled_filter`

Indicators

Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.

FieldKindValues
AllowUserConsentForRiskyAppslike
  • "%true%"
Operationeq
  • "Update authorization policy."
Workloadeq
  • AzureActiveDirectory
index_numberge
  • 0
sourcetypeeq
  • o365:management:activity