Azure Active Directory security operations for Privileged Identity Management

Article
09/16/2022
8 minutes to read

The security of business assets depends on the integrity of the privileged accounts that administer your IT systems. Cyber-attackers use credential theft attacks to target admin accounts and other privileged access accounts to try gaining access to sensitive data.

For cloud services, prevention and response are the joint responsibilities of the cloud service provider and the customer.

Traditionally, organizational security has focused on the entry and exit points of a network as the security perimeter. However, SaaS apps and personal devices have made this approach less effective. In Azure Active Directory (Azure AD), we replace the network security perimeter with authentication in your organization's identity layer. As users are assigned to privileged administrative roles, their access must be protected in on-premises, cloud, and hybrid environments.

You're entirely responsible for all layers of security for your on-premises IT environment. When you use Azure cloud services, prevention and response are joint responsibilities of Microsoft as the cloud service provider and you as the customer.

For more information on the shared responsibility model, see Shared responsibility in the cloud.
For more information on securing access for privileged users, see Securing Privileged access for hybrid and cloud deployments in Azure AD.
For a wide range of videos, how-to guides, and content of key concepts for privileged identity, visit Privileged Identity Management documentation.

Privileged Identity Management (PIM) is an Azure AD service that enables you to manage, control, and monitor access to important resources in your organization. These resources include resources in Azure AD, Azure, and other Microsoft Online Services such as Microsoft 365 or Microsoft Intune. You can use PIM to help mitigate the following risks:

Identify and minimize the number of people who have access to secure information and resources.
Detect excessive, unnecessary, or misused access permissions on sensitive resources.
Reduce the chances of a malicious actor getting access to secured information or resources.
Reduce the possibility of an unauthorized user inadvertently impacting sensitive resources.

Use this article provides guidance to set baselines, audit sign-ins, and usage of privileged accounts. Use the source audit log source to help maintain privileged account integrity.

Where to look

The log files you use for investigation and monitoring are:

In the Azure portal, view the Azure AD Audit logs and download them as comma-separated value (CSV) or JavaScript Object Notation (JSON) files. The Azure portal has several ways to integrate Azure AD logs with other tools to automate monitoring and alerting:

Microsoft Sentinel – enables intelligent security analytics at the enterprise level by providing security information and event management (SIEM) capabilities.
Sigma rules - Sigma is an evolving open standard for writing rules and templates that automated management tools can use to parse log files. Where Sigma templates exist for our recommended search criteria, we've added a link to the Sigma repo. The Sigma templates aren't written, tested, and managed by Microsoft. Rather, the repo and templates are created and collected by the worldwide IT security community.
Azure Monitor – enables automated monitoring and alerting of various conditions. Can create or use workbooks to combine data from different sources.
Azure Event Hubs integrated with a SIEM- Azure AD logs can be integrated to other SIEMs such as Splunk, ArcSight, QRadar, and Sumo Logic via the Azure Event Hubs integration.
Microsoft Defender for Cloud Apps – enables you to discover and manage apps, govern across apps and resources, and check your cloud apps’ compliance.
Securing workload identities with Identity Protection Preview - Used to detect risk on workload identities across sign-in behavior and offline indicators of compromise.

The rest of this article has recommendations to set a baseline to monitor and alert on, with a tier model. Links to pre-built solutions appear after the table. You can build alerts using the preceding tools. The content is organized into the following areas:

Baselines
Azure AD role assignment
Azure AD role alert settings
Azure resource role assignment
Access management for Azure resources
Elevated access to manage Azure subscriptions

Baselines

The following are recommended baseline settings:

What to monitor	Risk level	Recommendation	Roles	Notes
Azure AD roles assignment	High	Require justification for activation.Require approval to activate. Set two-level approver process. On activation, require Azure AD Multi-Factor Authentication (MFA). Set maximum elevation duration to 8 hrs.	Privileged Role Administration, Global Administrator	A privileged role administrator can customize PIM in their Azure AD organization, including changing the experience for users activating an eligible role assignment.
Azure Resource Role Configuration	High	Require justification for activation. Require approval to activate. Set two-level approver process. On activation, require Azure AD Multi-Factor Authentication. Set maximum elevation duration to 8 hrs.	Owner, Resource Administrator, User Access, Administrator, Global Administrator, Security Administrator	Investigate immediately if not a planned change. This setting might enable attacker access to Azure subscriptions in your environment.

Azure AD roles assignment

A privileged role administrator can customize PIM in their Azure AD organization, which includes changing the user experience of activating an eligible role assignment:

Prevent bad actor to remove Azure AD Multi-Factor Authentication requirements to activate privileged access.
Prevent malicious users bypass justification and approval of activating privileged access.

What to monitor	Risk level	Where	Filter/sub-filter	Notes
Alert on Add changes to privileged account permissions	High	Azure AD Audit logs	Category = Role Management -and- Activity Type – Add eligible member (permanent) -and- Activity Type – Add eligible member (eligible) -and- Status = Success/failure -and- Modified properties = Role.DisplayName	Monitor and always alert for any changes to privileged role administrator and global administrator. This can be an indication an attacker is trying to gain privilege to modify role assignment settings. If you don’t have a defined threshold, alert on 4 in 60 minutes for users and 2 in 60 minutes for privileged accounts. Microsoft Sentinel template Sigma rules
Alert on bulk deletion changes to privileged account permissions	High	Azure AD Audit logs	Category = Role Management -and- Activity Type – Remove eligible member (permanent) -and- Activity Type – Remove eligible member (eligible) -and- Status = Success/failure -and- Modified properties = Role.DisplayName	Investigate immediately if not a planned change. This setting could enable an attacker access to Azure subscriptions in your environment. Microsoft Sentinel template Sigma rules
Changes to PIM settings	High	Azure AD Audit Log	Service = PIM -and- Category = Role Management -and- Activity Type = Update role setting in PIM -and- Status Reason = MFA on activation disabled (example)	Monitor and always alert for any changes to Privileged Role Administrator and Global Administrator. This can be an indication an attacker has access to modify role assignment settings. One of these actions could reduce the security of the PIM elevation and make it easier for attackers to acquire a privileged account. Microsoft Sentinel template Sigma rules
Approvals and deny elevation	High	Azure AD Audit Log	Service = Access Review -and- Category = UserManagement -and- Activity Type = Request Approved/Denied -and- Initiated actor = UPN	All elevations should be monitored. Log all elevations to give a clear indication of timeline for an attack. Microsoft Sentinel template Sigma rules
Alert setting changes to disabled.	High	Azure AD Audit logs	Service =PIM -and- Category = Role Management -and- Activity Type = Disable PIM Alert -and- Status = Success /Failure	Always alert. Helps detect bad actor removing alerts associated with Azure AD Multi-Factor Authentication requirements to activate privileged access. Helps detect suspicious or unsafe activity. Microsoft Sentinel template Sigma rules

For more information on identifying role setting changes in the Azure AD Audit log, see View audit history for Azure AD roles in Privileged Identity Management.

Azure resource role assignment

Monitoring Azure resource role assignments allows visibility into activity and activations for resources roles. These assignments might be misused to create an attack surface to a resource. As you monitor for this type of activity, you're trying to detect:

Query role assignments at specific resources
Role assignments for all child resources
All active and eligible role assignment changes

What to monitor	Risk level	Where	Filter/sub-filter	Notes
Audit Alert Resource Audit log for Privileged account activities	High	In PIM, under Azure Resources, Resource Audit	Action: Add eligible member to role in PIM completed (time bound) -and- Primary Target -and- Type User -and- Status = Succeeded	Always alert. Helps detect bad actor adding eligible roles to manage all resources in Azure.
Audit Alert Resource Audit for Disable Alert	Medium	In PIM, under Azure Resources, Resource Audit	Action: Disable Alert -and- Primary Target: Too many owners assigned to a resource -and- Status = Succeeded	Helps detect bad actor disabling alerts, in the Alerts pane, which can bypass malicious activity being investigated
Audit Alert Resource Audit for Disable Alert	Medium	In PIM, under Azure Resources, Resource Audit	Action: Disable Alert -and- Primary Target: Too many permanent owners assigned to a resource -and- Status = Succeeded	Prevent bad actor from disable alerts, in the Alerts pane, which can bypass malicious activity being investigated
Audit Alert Resource Audit for Disable Alert	Medium	In PIM, under Azure Resources, Resource Audit	Action: Disable Alert -and- Primary Target Duplicate role created -and- Status = Succeeded	Prevent bad actor from disable alerts, from the Alerts pane, which can bypass malicious activity being investigated

For more information on configuring alerts and auditing Azure resource roles, see:

Access management for Azure resources and subscriptions

Users or group members assigned the Owner or User Access Administrator subscriptions roles, and Azure AD Global Administrators who enabled subscription management in Azure AD, have Resource Administrator permissions by default. The administrators assign roles, configure role settings, and review access using Privileged Identity Management (PIM) for Azure resources.

A user who has Resource administrator permissions can manage PIM for Resources. Monitor for and mitigate this introduced risk: the capability can be used to allow bad actors privileged access to Azure subscription resources, such as virtual machines (VMs) or storage accounts.

What to monitor	Risk level	Where	Filter/sub-filter	Notes
Elevations	High	Azure AD, under Manage, Properties	Periodically review setting. Access management for Azure resources	Global administrators can elevate by enabling Access management for Azure resources. Verify bad actors haven't gained permissions to assign roles in all Azure subscriptions and management groups associated with Active Directory.