Techniques
Sample rules
O365 User Consent Blocked for Risky Application
- source: splunk
- technicques:
- T1528
Description
The following analytic identifies instances where Office 365 has blocked a user’s attempt to grant consent to an application deemed risky or potentially malicious. This suggests that the application has exhibited behaviors or characteristics that are commonly associated with malicious intent or poses a security risk. This detection leverages the O365 audit logs, specifically focusing on events related to user consent actions and system-driven blocks. By filtering for blocked consent actions associated with applications, the analytic highlights instances where O365’s built-in security measures have intervened. Applications that are flagged and blocked by O365 typically exhibit suspicious characteristics or behaviors. Monitoring for these blocked consent attempts helps security teams identify potential threats early on and can provide insights into users who might be targeted or susceptible to such risky applications. It’s an essential layer of defense in ensuring that malicious or risky applications don’t gain access to organizational data. If the detection is a true positive, it indicates that the built-in security measures of O365 successfully prevented a potentially harmful application from gaining access. However, the attempt itself suggests that either a user might be targeted or that there’s a presence of malicious applications trying to infiltrate the organization. Immediate investigation is required to understand the context of the block and to take further preventive measures.
Detection logic
`o365_management_activity` Workload=AzureActiveDirectory Operation="Consent to application." ResultStatus=Failure
| eval permissions =mvindex('ModifiedProperties{}.NewValue', 4)
| eval reason =mvindex('ModifiedProperties{}.NewValue', 5)
| search reason = "Risky application detected"
| rex field=permissions "Scope: (?<Scope>[^,]+)"
| stats max(_time) as lastTime by Operation, user, reason, object, Scope
| `security_content_ctime(lastTime)`
| `o365_user_consent_blocked_for_risky_application_filter`