Listen to this Post
Introduction:
A recent social media post by a Microsoft security expert has ignited a firestorm, revealing a critical knowledge gap in cloud identity management. What was presented as an innocuous command for querying Seamless Single Sign-On (SSO) audit logs has been implicated in a potential security incident, highlighting the immense power and inherent risk of the Microsoft Graph API.
Learning Objectives:
- Understand the function and potential security implications of the Microsoft Graph API and PowerShell cmdlets like
Invoke-MgGraphRequest. - Learn how to securely query, monitor, and lock down audit logs and sign-in events within Microsoft Entra ID (Azure AD).
- Implement defensive configurations and monitoring to detect and prevent unauthorized access and command execution.
You Should Know:
1. The Anatomy of the Controversial Command
The command in question is a PowerShell cmdlet that interfaces with Microsoft’s cloud services.
This command queries the sign-in logs for a specific application ID Invoke-MgGraphRequest -Uri "https://graph.microsoft.com/v1.0/auditLogs/signIns?`$filter=appId eq '00000002-0000-0000-c000-000000000000'"
Step-by-step guide: This command uses the `Invoke-MgGraphRequest` cmdlet from the Microsoft Graph PowerShell SDK. It sends a GET request to the specified URI, which is the Microsoft Graph API endpoint for sign-in logs (/auditLogs/signIns). The `$filter` query parameter is used to narrow down the results to show only sign-in events related to the Microsoft Azure Active Directory application, identified by the well-known appId 00000002-0000-0000-c000-000000000000. To run this, you must first connect to MgGraph with sufficient permissions (AuditLog.Read.All and Directory.Read.All) using Connect-MgGraph -Scopes "AuditLog.Read.All", "Directory.Read.All". While the command itself is read-only and not malicious, its execution requires high privileges, and the act of running unknown commands from an untrusted source is a severe security violation.
2. Securing Your Microsoft Graph PowerShell Environment
Before executing any Graph queries, you must ensure your session is secure and least privilege is enforced.
1. Disconnect any existing sessions Disconnect-MgGraph <ol> <li>Connect with explicitly defined, minimal scopes Connect-MgGraph -Scopes "AuditLog.Read.All"</p></li> <li><p>Verify the permissions granted to your session (Get-MgContext).Scopes</p></li> <li><p>For sensitive operations, use Conditional Access to restrict which users can connect via PowerShell and from which locations.
Step-by-step guide: Never connect with broad scopes like `Directory.ReadWrite.All` unless absolutely necessary. Always verify the required permissions in the Microsoft Graph permissions reference. Use a dedicated, secure administrative workstation for such tasks. The `Disconnect-MgGraph` cmdlet ensures you are starting a fresh, authenticated session and not reusing potentially compromised credentials from a previous connection.
3. Proactive Monitoring for Graph API Activity
Detecting anomalous or unauthorized use of the Graph API is crucial for cloud security.
// Azure Sentinel / Microsoft Defender for Cloud KQL Query // Detects a high volume of Graph API requests from a single user/client app in a short time AuditLogs | where OperationName == "Export sign-in activity" | where Result == "success" | summarize StartTime = min(TimeGenerated), EndTime = max(TimeGenerated), Operations = count() by UserAgent, UserId, IPAddress | extend Duration = EndTime - StartTime | where Operations > 100 and Duration between(0min.. 30min) | project StartTime, EndTime, Duration, Operations, UserId, UserAgent, IPAddress
Step-by-step guide: This Kusto Query Language (KQL) query is designed for Azure Sentinel or Microsoft Defender logs. It looks for successful “Export sign-in activity” operations, which could indicate someone exfiltrating sign-in data. It then groups these events by user, user agent, and IP address, and flags any session that performs an unusually high number of operations (>100) within a 30-minute window. This can be a sign of reconnaissance or data gathering by an attacker. This query should be deployed as a custom detection rule with a medium to high severity alert.
4. Hardening Entra ID Against Unauthorized Application Access
The core of many attacks is abusing application permissions. Regular audits are mandatory.
1. Get all Service Principals (Enterprise Applications) and their permissions
Get-MgServicePrincipal -All | Where-Object { $<em>.PublisherName -notlike "Microsoft" } | ForEach-Object {
$sp = $</em>
$perms = Get-MgServicePrincipalOauth2PermissionGrant -ServicePrincipalId $sp.Id
[bash]@{
ApplicationName = $sp.DisplayName
ApplicationId = $sp.AppId
Publisher = $sp.PublisherName
Permissions = ($perms.Scope -join ", ")
}
}
<ol>
<li>Review and Revoke overly permissive OAuth grants (CAUTION)
Get-MgOauth2PermissionGrant -All | Where-Object { $<em>.Scope -eq "Directory.ReadWrite.All" } | ForEach-Object {
Remove-MgOauth2PermissionGrant -OAuth2PermissionGrantId $</em>.Id Confirm carefully before running Remove-
}
Step-by-step guide: The first script retrieves all service principals (excluding Microsoft-owned ones) and lists their granted OAuth2 permission scopes. This helps identify third-party applications with excessive permissions like `Directory.ReadWrite.All` or Mail.ReadWrite. The second script finds and can remove those excessive grants. This should be run in a test environment first. The principle of least privilege must be applied to applications just as it is to users.
5. Implementing Detective Controls for PowerShell Usage
Logging and monitoring all PowerShell activity is non-negotiable for modern SOCs.
Enable Module Logging and Script Block Logging via Group Policy or locally This is done via the PowerShell policy, not a PS command itself. Alternatively, in Windows, enable detailed auditing via command line: auditpol /set /subcategory:"PowerShell Execution" /success:enable /failure:enable A SIEM query to detect the use of Invoke-MgGraphRequest DeviceProcessEvents | where ProcessVersionInfoOriginalFileName =~ "pwsh.dll" or ProcessVersionInfoOriginalFileName =~ "powershell.exe" | where ProcessCommandLine contains "Invoke-MgGraphRequest" | project Timestamp, DeviceName, AccountName, ProcessCommandLine, InitiatingProcessParentFileName
Step-by-step guide: Defender for Endpoint or a similar EDR solution is required for the KQL query to work. The query filters process events for PowerShell hosts (pwsh.dll for PowerShell Core, `powershell.exe` for Windows PowerShell) and then looks for command lines containing the specific `Invoke-MgGraphRequest` cmdlet. This provides a detective control to alert on the use of powerful Graph API commands, allowing security teams to verify their legitimacy. The `auditpol` command enables deeper Windows auditing to capture these events in the first place.
6. The Zero-Trust Response: Assume a Breach
If a suspicious command is run, immediate isolation and investigation are required.
1. Immediately force sign-out of all sessions for a potentially compromised user Revoke-MgUserSignInSession -UserId <compromised_user_id> <ol> <li>Disable the user account Update-MgUser -UserId <compromised_user_id> -AccountEnabled:$false</p></li> <li><p>Initiate a password reset for the user (Often done via the Admin Portal, not directly via Graph for clarity)</p></li> <li><p>Check for new application consents granted around the time of the incident Get-MgOauth2PermissionGrant -Filter "ConsentProvidedDateTime gt <incident_start_time>" | Select-Object ClientId, Scope, ConsentType
Step-by-step guide: This incident response playbook uses Graph commands to contain a potential breach. `Revoke-MgUserSignInSession` invalidates all refresh tokens for the user, effectively logging them out of all devices and applications immediately. Disabling the account prevents any new authentication attempts. The final step checks the audit log for any new OAuth2 permission grants that might have been added by an attacker during the compromise window, a common technique for persistence.
What Undercode Say:
- The Tool is Not the Threat: The `Invoke-MgGraphRequest` command itself is a legitimate and powerful administrative tool. The critical failure was in operational security: the execution of an unsolicited command from an unvetted source by a privileged user.
- The Blurred Lines of Social Engineering: This incident represents a sophisticated form of social engineering within a professional community. It exploits trust among experts and leverages their curiosity about a relevant technical topic, bypassing traditional user-focused phishing defenses.
The incident described in the LinkedIn thread, whether a misunderstanding, joke, or actual compromise, serves as a perfect case study. It underscores that the most advanced cloud environments can be undermined by the most fundamental human vulnerabilities. Security postures that focus exclusively on technical controls while neglecting procedural controls—like change management and strict policies against running ad-hoc commands—are inherently fragile. The community’s reaction demonstrates a need for better education on the shared responsibility model in the cloud, where administrators wield god-like tools that require god-like discipline.
Prediction:
This event is a precursor to a new wave of social engineering attacks targeting IT professionals and developers within their native environments—Slack, Teams, GitHub issues, and professional forums like LinkedIn. Attackers will increasingly weaponize legitimate API queries and CLI commands, knowing they can bypass traditional security filters designed to catch obvious malware. We will see a rise in “living-off-the-land” attacks for cloud environments, using native tools like Graph API, Azure CLI, and PowerShell to perform reconnaissance, lateral movement, and data exfiltration without triggering any anti-malware alerts. This will force a paradigm shift in cloud security monitoring from looking for known-bad commands to profiling normal behavior and flagging anomalous sequences of otherwise legitimate administrative actions.
🎯Let’s Practice For Free:
IT/Security Reporter URL:
Reported By: Nathanmcnulty Graphmicrosoftcomv10auditlogssignins – Hackers Feeds
Extra Hub: Undercode MoN
Basic Verification: Pass ✅
