Background

Just wrapped up an Active Directory Pentest and learned quite a lot of things! Some of this I figured out myself, some with the help from the talented @slygoo :smile:

Gonna do a write-up/dump so I can refer back in the future…

Tips & Tricks

  • Powershell $FormatEnumerationLimit=-1 will make it so your output doesn’t get truncated if you output it in Table / List format.

Random Pentest Tool knowledge

  • cme/netexec has an audit mode which auto-masks all passwords. You can set it in the config file

  • similarly you can also change the Pwn3d! text to something more formal if you wish

  • Group3r is amazing at displaying Group Policy at a glance, and also helps you find “findings”
  • Always try using native Windows methods over attack-tooling as this is less likely to get caught.
    • Enter-PSSession vs Evil-WinRM
    • RDP vs xfreerdp
    • CMMC vs net
    • ADExplorer vs SharpHound etc.
  • go-secdump - another alternative remote dumping tool
  • DPAT module in Max - great domain password audit tool that also shows breakdown by domain groups/categories etc.

Random AD knowledge

  • SeMachinePrivilege controls who / which group can add computers to the domain. One hardening step is to set it to Administrators only
  • GPOs are a great way to catch overprivileged assignment of privs against a group of principals for example
  • SPNs don’t have to be valid, so if you see a user with an invalid but non-empty SPN string call it out as it only increases the risk of compromise as that user can now be kerberoasted.

LDAP / Relaying

  • LDAP Signing is for protecting LDAP 389
    • You cannot relay SMB to LDAP
    • UNLESS you combine with NTLMv1 and Drop the Mic
    • You can relay HTTP to LDAP, either through link clicks or by using WebDAV + Coercion etc. Syntax is \SERVER@PORT\PATH
  • LDAP Binding is for protecting LDAPS 636
    • You can technically auth SMB to LDAPS but not relay
  • You can smuggle sensitive LDAPS operations through LDAP if signing is OFF but binding is ON via StartTLS, modern versions of impacket handle this transparently already :)

MSSQL

  • Don’t discount MSSQL servers / service accounts as weakly configured permissions may let you escalate on servers or hop around links
  • When PowerUpSQL says a server is ‘Accessible’, it has filtered down to servers that are a) connectable and b) your user has privs
    • Therefore, there might still be a couple servers out there that are browsable, just you might need a different user :)

RBCD

  • Is not just about adding users, its a two part attack
    • You can add computer or trick a privileged entity to add a computer account you can control
    • Either a target machine or service is misconfigured, OR you have write permissions over that object
    • Can add the DelegateTo attribute on target and set it to our computer object
    • Our computer object can then delegate as a user against target service similar to silver ticket once granted privs
  • Inbound Object Controller - what things can control current account
  • Oubound Object Controller - what things can current account control
  • In some views, nodes can be further ‘Expanded’ to reveal all sub-nodes, handy for viz
  • Direct Membership / Unrolled Membership - see what groups current account belongs to
  • Direct Members / Unrolled Members - see members / sub-members of a group
  • space can be used to see all nodes on a graph
  • ctrl can be used to toggle node labels on/off
  • start and end nodes can be used to plot a nice graph showcasing an attack path