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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.

  • Type: TTP
  • Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
  • Datamodel: Risk
  • Last Updated: 2024-05-26
  • Author: Mauricio Velazco, Splunk
  • ID: 12a23592-e3da-4344-8545-205d3290647c

Annotations

ATT&CK

ATT&CK

ID Technique Tactic
T1562 Impair Defenses Defense Evasion
Kill Chain Phase
  • Exploitation
NIST
  • DE.CM
CIS20
  • CIS 10
CVE 


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`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%" 
| stats count min(_time) as firstTime max(_time) as lastTime by user, Operation, AllowUserConsentForRiskyApps, user_agent 
| `security_content_ctime(firstTime)` 
| `security_content_ctime(lastTime)` 
| `o365_block_user_consent_for_risky_apps_disabled_filter`

Macros

The SPL above uses the following Macros:

:information_source: o365_block_user_consent_for_risky_apps_disabled_filter is a empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.

Required fields

List of fields required to use this analytic.

  • _time
  • Workload
  • Operation
  • ModifiedProperties{}.Name
  • ModifiedProperties{}.NewValue
  • user
  • user_agent

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.

Associated Analytic Story

RBA

Risk Score Impact Confidence Message
30.0 60 50 Risk-based step-up consent security setting was disabled by $user$

:information_source: The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.

Reference

Test Dataset

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 | version: 2