Azure AD User Consent Denied for OAuth Application
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.
- Type: TTP
-
Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
- Last Updated: 2024-05-18
- Author: Mauricio Velazco, Splunk
- ID: bb093c30-d860-4858-a56e-cd0895d5b49c
Annotations
Kill Chain Phase
- Exploitation
NIST
- DE.CM
CIS20
- CIS 10
CVE
Search
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`azure_monitor_aad` operationName="Sign-in activity" properties.status.errorCode=65004
| rename properties.* as *
| stats count min(_time) as firstTime max(_time) as lastTime by operationName, user, appDisplayName, status.failureReason
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)`
| `azure_ad_user_consent_denied_for_oauth_application_filter`
Macros
The SPL above uses the following Macros:
azure_ad_user_consent_denied_for_oauth_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.status.errorCode
- user
- properties.appDisplayName
- status.failureReason
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.
Associated Analytic Story
RBA
Risk Score | Impact | Confidence | Message |
---|---|---|---|
36.0 | 60 | 60 | User $user$ denied consent for an OAuth application. |
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
- 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
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: 3