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PowerShell MachineAccountQuota and DNS exploit tools

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MachineAccountQuota Functions

The default Active Directory ms-DS-MachineAccountQuota attribute setting allows all domain users to add up to 10 machine accounts to a domain. Powermad includes a set of functions for exploiting ms-DS-MachineAccountQuota without attaching an actual system to AD.

Get-MachineAccountAttribute

This function can return values populated in a machine account attribute.

Example:

Get-MachineAccountCreator

This function leverages the ms-DS-CreatorSID property on machine accounts to return a list of usernames or SIDs and the associated machine account. The ms-DS-CreatorSID property is only populated when a machine account is created by an unprivileged user.

Example:

Disable-MachineAccount

This function can disable a machine account that was added through New-MachineAccount. This function should be used with the same user that created the machine account.

Example:

Enable-MachineAccount

This function can enable a machine account that was disabled through Disable-MachineAccount. This function should be used with the same user that created the machine account.

Example:

New-MachineAccount

This function can add a new machine account directly through an LDAP add request to a domain controller and not by impacting the host system’s attachment status to Active Directory.

The LDAP add request is modeled after the add request used when joining a system to a domain. The following (mostly validated by the DC) attributes are set:

A new machine account can be used for tasks such as leveraging privilege provided to the ‘Domain Computers’ group or as an additional account for domain enumeration, DNS exploits, etc. By default, machine accounts do not have logon locally permission. You can either use tools/clients that accept network credentials directly or through the use of ‘runsas /netonly’ or @harmj0y’s Invoke-UserImpersonation/Invoke-RevertToSelf included with PowerView.

Machine accounts created with standard users will have the mS-DS-CreatorSID populated with the standard user’s SID.

Note that ms-DS-MachineAccountQuota does not provide the ability for authenticated users to delete added machine accounts from AD. Elevated privilege will need to be acquired to remove the account if you want to avoid passing the task off to your client.

Examples:

Remove-MachineAccount

This function removes a machine account with a privileged account.

Example:

Set-MachineAccountAttribute

This function can populate some attributes for an account that was added through New-MachineAccount, if a user has write access. This function should be used with the same user that created the machine account.

Here is a list of some of the usual write access enabled attributes:

Examples:

Invoke-AgentSmith

This function leverages New-MachineAccount to recursively create as many machine accounts as possible from a single unprivileged account through MachineAccountQuota. See the following blog post for details:

DNS Functions

By default, authenticated users have the 'Create all child objects' permission on the Active Directory-Integrated DNS (ADIDNS) zone. Most records that do not currently exist in an AD zone can be added/deleted.

Dynamic Updates Functions

Invoke-DNSUpdate

This function can be used to add/delete dynamic DNS records if the default setting of enabled secure dynamic updates is configured on a domain controller. A, AAAA, CNAME, MX, PTR, SRV, and TXT records are currently supported. Invoke-DNSUpdate is modeled after BIND`s nsupdate tool when using the '-g' or 'gsstsig' options.

Examples:

ADIDNS Functions

Disable-ADIDNSNode

This function can tombstone an ADIDNS node.

Example:

*Tombstone a wildcard record.
`Disable-ADIDNSNode -Node *

Enable-ADIDNSNode

This function can turn a tombstoned node back into a valid record.

Example:

Get-ADIDNSNodeAttribute

This function can return values populated in a DNS node attribute.

Example:

Get-ADIDNSNodeOwner

This function can return the owner of an ADIDNS Node.

Example:

Get-ADIDNSPermission

This function gets a DACL of an ADIDNS node or zone.

Examples:

Get-ADIDNSZone

This function can return ADIDNS zones.

Examples:

Grant-ADIDNSPermission

This function adds an ACE to a DNS node or zone DACL.

Example:

New-ADIDNSNode

This function adds a DNS node to an Active Directory-Integrated DNS (ADIDNS) Zone through an encrypted LDAP add request.

Example:

New-DNSRecordArray

This function creates a valid byte array for the dnsRecord attribute.

Example:

New-SOASerialNumberArray

This function gets the current SOA serial number for a DNS zone and increments it by the set amount.

Example:

Rename-ADIDNSNode

This function can rename a DNS node.

Example:

Remove-ADIDNSNode

This function can remove a DNS node.

Example:

Revoke-ADIDNSPermission

This function removes an ACE to a DNS node or zone DACL.

Example:

Set-ADIDNSNodeAttribute

This function can append, populate, or overwrite values in a DNS node attribute.

Example:

Set-ADIDNSNodeOwner

This function can set the owner of a DNS Node. Note that a token with SeRestorePrivilege is required.

Example:

Miscellaneous Functions

Get-KerberosAESKey

This function can generate Kerberos AES 256 and 128 keys from a known username and password. This can be used to test pass the hash in invoke-DNSUpdate.

Example: