ID | Technique | Tactic |
---|---|---|
T1586 | Compromise Accounts | Resource Development |
T1586.003 | Cloud Accounts | Resource Development |
T1556 | Modify Authentication Process | Credential Access |
T1556.006 | Multi-Factor Authentication | Defense Evasion |
Detection: Azure AD Multi-Factor Authentication Disabled
Description
The following analytic detects attempts to disable multi-factor authentication (MFA) for an Azure AD user. It leverages Azure Active Directory AuditLogs to identify the "Disable Strong Authentication" operation. This activity is significant because disabling MFA can allow adversaries to maintain persistence using compromised accounts without raising suspicion. If confirmed malicious, this action could enable attackers to bypass an essential security control, potentially leading to unauthorized access and prolonged undetected presence in the environment.
Search
1`azure_monitor_aad` category=AuditLogs operationName="Disable Strong Authentication"
2| rename properties.* as *
3| rename targetResources{}.type as type
4| rename initiatedBy.user.userPrincipalName as initiatedBy
5| stats count min(_time) as firstTime max(_time) as lastTime by user, type, operationName, initiatedBy, result
6| `security_content_ctime(firstTime)`
7| `security_content_ctime(lastTime)`
8| `azure_ad_multi_factor_authentication_disabled_filter`
Data Source
Name | Platform | Sourcetype | Source |
---|---|---|---|
Azure Active Directory Disable Strong Authentication | Azure | 'azure:monitor:aad' |
'Azure AD' |
Macros Used
Name | Value |
---|---|
azure_monitor_aad | sourcetype=azure:monitor:aad |
azure_ad_multi_factor_authentication_disabled_filter | search * |
azure_ad_multi_factor_authentication_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 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 AuditLogs log category.
Known False Positives
Legitimate use case may require for users to disable MFA. Filter as needed.
Associated Analytic Story
Risk Based Analytics (RBA)
Risk Message | Risk Score | Impact | Confidence |
---|---|---|---|
MFA disabled for User $user$ initiated by $initiatedBy$ | 45 | 50 | 90 |
References
-
https://docs.microsoft.com/en-us/azure/active-directory/authentication/concept-mfa-howitworks
-
https://docs.microsoft.com/en-us/azure/active-directory/authentication/howto-mfa-userstates
Detection Testing
Test Type | Status | Dataset | Source | Sourcetype |
---|---|---|---|---|
Validation | ✅ Passing | N/A | N/A | N/A |
Unit | ✅ Passing | Dataset | Azure AD |
azure:monitor:aad |
Integration | ✅ Passing | Dataset | Azure AD |
azure:monitor:aad |
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: 4