Try in Splunk Security Cloud

Description

The following analytic detects instances where Azure AD has blocked a user's attempt to grant consent to a risky or potentially malicious application. This detection leverages Azure AD audit logs, focusing on user consent actions and system-driven blocks. Monitoring these blocked consent attempts is crucial as it highlights potential threats early on, indicating that a user might be targeted or that malicious applications are attempting to infiltrate the organization. If confirmed malicious, this activity suggests that Azure's security measures successfully prevented a harmful application from accessing organizational data, warranting immediate investigation to understand the context and take preventive measures.

  • Type: TTP
  • Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
  • Datamodel: Risk
  • Last Updated: 2024-05-30
  • Author: Mauricio Velazco, Splunk
  • ID: 06b8ec9a-d3b5-4882-8f16-04b4d10f5eab

Annotations

ATT&CK

ATT&CK

ID Technique Tactic
T1528 Steal Application Access Token Credential Access
Kill Chain Phase
  • Exploitation
NIST
  • DE.CM
CIS20
  • CIS 10
CVE 


1
2
3
4
5
6
7
8
9
10
11
12
13



`azure_monitor_aad` operationName="Consent to application" properties.result=failure 
| rename properties.* as *  
| eval reason_index = if(mvfind('targetResources{}.modifiedProperties{}.displayName', "ConsentAction.Reason") >= 0, mvfind('targetResources{}.modifiedProperties{}.displayName', "ConsentAction.Reason"), -1) 
| eval permissions_index = if(mvfind('targetResources{}.modifiedProperties{}.displayName', "ConsentAction.Permissions") >= 0, mvfind('targetResources{}.modifiedProperties{}.displayName', "ConsentAction.Permissions"), -1) 
| search reason_index >= 0  
| eval reason = mvindex('targetResources{}.modifiedProperties{}.newValue',reason_index) 
| eval permissions = mvindex('targetResources{}.modifiedProperties{}.newValue',permissions_index) 
| search reason = "\"Risky application detected\"" 
| rex field=permissions "Scope: (?<Scope>[^,]+)" 
| stats count min(_time) as firstTime max(_time) as lastTime by operationName, user, reason, Scope 
| `security_content_ctime(firstTime)` 
| `security_content_ctime(lastTime)` 
| `azure_ad_user_consent_blocked_for_risky_application_filter`

Macros

The SPL above uses the following Macros:

:information_source: azure_ad_user_consent_blocked_for_risky_application_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
  • operationName
  • properties.result
  • properties.targetResources{}.modifiedProperties{}.displayName
  • properties.targetResources{}.modifiedProperties{}.newValue

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 AuditLog log category.

Known False Positives

UPDATE_KNOWN_FALSE_POSITIVES

Associated Analytic Story

RBA

Risk Score Impact Confidence Message
30.0 30 100 Azure AD has blocked $user$ attempt to grant to consent to an application deemed risky.

: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