ID | Technique | Tactic |
---|---|---|
T1562 | Impair Defenses | Defense Evasion |
Detection: O365 Block User Consent For Risky Apps Disabled
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.
Search
1`o365_management_activity` Workload=AzureActiveDirectory Operation="Update authorization policy."
2| eval index_number = if(mvfind('ModifiedProperties{}.Name', "AllowUserConsentForRiskyApps") >= 0, mvfind('ModifiedProperties{}.Name', "AllowUserConsentForRiskyApps"), -1)
3| search index_number >= 0
4| eval AllowUserConsentForRiskyApps = mvindex('ModifiedProperties{}.NewValue',index_number)
5| where AllowUserConsentForRiskyApps like "%true%"
6| stats count min(_time) as firstTime max(_time) as lastTime by user, Operation, AllowUserConsentForRiskyApps, user_agent
7| `security_content_ctime(firstTime)`
8| `security_content_ctime(lastTime)`
9| `o365_block_user_consent_for_risky_apps_disabled_filter`
Data Source
Name | Platform | Sourcetype | Source |
---|---|---|---|
O365 Update authorization policy. | N/A | 'o365:management:activity' |
'o365' |
Macros Used
Name | Value |
---|---|
o365_management_activity | sourcetype=o365:management:activity |
o365_block_user_consent_for_risky_apps_disabled_filter | search * |
o365_block_user_consent_for_risky_apps_disabled_filter
is an empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.
Annotations
Default Configuration
This detection is configured by default in Splunk Enterprise Security to run with the following settings:
Setting | Value |
---|---|
Disabled | true |
Cron Schedule | 0 * * * * |
Earliest Time | -70m@m |
Latest Time | -10m@m |
Schedule Window | auto |
Creates Notable | Yes |
Rule Title | %name% |
Rule Description | %description% |
Notable Event Fields | user, dest |
Creates Risk Event | True |
Implementation
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.
Associated Analytic Story
Risk Based Analytics (RBA)
Risk Message | Risk Score | Impact | Confidence |
---|---|---|---|
Risk-based step-up consent security setting was disabled by $user$ | 30 | 60 | 50 |
References
-
https://goodworkaround.com/2020/10/19/a-look-behind-the-azure-ad-permission-classifications-preview/
-
https://learn.microsoft.com/en-us/defender-cloud-apps/investigate-risky-oauth
Detection Testing
Test Type | Status | Dataset | Source | Sourcetype |
---|---|---|---|---|
Validation | ✅ Passing | N/A | N/A | N/A |
Unit | ✅ Passing | Dataset | O365 |
o365:management:activity |
Integration | ✅ Passing | Dataset | O365 |
o365:management:activity |
Replay any dataset to Splunk Enterprise by using our replay.py
tool or the UI.
Alternatively you can replay a dataset into a Splunk Attack Range
Source: GitHub | Version: 3