AD Privilege Escalation

Kerberoast

WUT IS DIS?: All standard domain users can request a copy of all service accounts along with their correlating password hashes, so we can ask a TGS for any SPN that is bound to a "user" account, extract the encrypted blob that was encrypted using the user's password and bruteforce it offline.

  • PowerView:

#Get User Accounts that are used as Service Accounts
Get-NetUser -SPN

#Get every available SPN account, request a TGS and dump its hash
Invoke-Kerberoast

#Requesting the TGS for a single account:
Request-SPNTicket
  
#Export all tickets using Mimikatz
Invoke-Mimikatz -Command '"kerberos::list /export"'

  • AD Module:

#Get User Accounts that are used as Service Accounts
Get-ADUser -Filter {ServicePrincipalName -ne "$null"} -Properties ServicePrincipalName

  • Impacket:

python GetUserSPNs.py <DomainName>/<DomainUser>:<Password> -outputfile <FileName>

  • Rubeus:

ASREPRoast

WUT IS DIS?: If a domain user account do not require kerberos preauthentication, we can request a valid TGT for this account without even having domain credentials, extract the encrypted blob and bruteforce it offline.

  • PowerView: Get-DomainUser -PreauthNotRequired -Verbose

  • AD Module: Get-ADUser -Filter {DoesNoteRequirePreAuth -eq $True} -Properties DoesNoteRequirePreAuth

Forcefully Disable Kerberos Preauth on an account i have Write Permissions or more! Check for interesting permissions on accounts:

Hint: We add a filter e.g. RDPUsers to get "User Accounts" not Machine Accounts, because Machine Account hashes are not crackable!

PowerView:

And finally execute the attack using the ASREPRoast tool.

Using Rubeus:

Using Impacket:

Password Spray Attack

If we have harvest some passwords by compromising a user account, we can use this method to try and exploit password reuse on other domain accounts.

Tools:

Force Set SPN

WUT IS DIS ?: If we have enough permissions -> GenericAll/GenericWrite we can set a SPN on a target account, request a TGS, then grab its blob and bruteforce it.

  • PowerView:

  • AD Module:

Finally use any tool from before to grab the hash and kerberoast it!

Abusing Shadow Copies

If you have local administrator access on a machine try to list shadow copies, it's an easy way for Domain Escalation.

  1. You can dump the backuped SAM database and harvest credentials.

  2. Look for DPAPI stored creds and decrypt them.

  3. Access backuped sensitive files.

List and Decrypt Stored Credentials using Mimikatz

Usually encrypted credentials are stored in:

  • %appdata%\Microsoft\Credentials

  • %localappdata%\Microsoft\Credentials

Detailed Article: DPAPI all the things

Unconstrained Delegation

WUT IS DIS ?: If we have Administrative access on a machine that has Unconstrained Delegation enabled, we can wait for a high value target or DA to connect to it, steal his TGT then ptt and impersonate him!

Using PowerView:

Note: We can also use Rubeus!

Constrained Delegation

Using PowerView and Kekeo:

ALTERNATIVE: Using Rubeus:

Now we can access the service as the impersonated user!

🚩 What if we have delegation rights for only a spesific SPN? (e.g TIME):

In this case we can still abuse a feature of kerberos called "alternative service". This allows us to request TGS tickets for other "alternative" services and not only for the one we have rights for. Thats gives us the leverage to request valid tickets for any service we want that the host supports, giving us full access over the target machine.

Resource Based Constrained Delegation

WUT IS DIS?: TL;DR If we have GenericALL/GenericWrite privileges on a machine account object of a domain, we can abuse it and impersonate ourselves as any user of the domain to it. For example we can impersonate Domain Administrator and have complete access.

Tools we are going to use:

First we need to enter the security context of the user/machine account that has the privileges over the object. If it is a user account we can use Pass the Hash, RDP, PSCredentials etc.

Exploitation Example:

Detailed Articles:

❗ In Constrain and Resource-Based Constrained Delegation if we don't have the password/hash of the account with TRUSTED_TO_AUTH_FOR_DELEGATION that we try to abuse, we can use the very nice trick "tgt::deleg" from kekeo or "tgtdeleg" from rubeus and fool Kerberos to give us a valid TGT for that account. Then we just use the ticket instead of the hash of the account to perform the attack.

Detailed Article: Rubeus – Now With More Kekeo

DNSAdmins Abuse

WUT IS DIS ?: If a user is a member of the DNSAdmins group, he can possibly load an arbitary DLL with the privileges of dns.exe that runs as SYSTEM. In case the DC serves a DNS, the user can escalate his privileges to DA. This exploitation process needs privileges to restart the DNS service to work.

  1. Enumerate the members of the DNSAdmins group:

    • PowerView: Get-NetGroupMember -GroupName "DNSAdmins"

    • AD Module: Get-ADGroupMember -Identiny DNSAdmins

  2. Once we found a member of this group we need to compromise it (There are many ways).

  3. Then by serving a malicious DLL on a SMB share and configuring the dll usage,we can escalate our privileges:

Abusing Active Directory-Integraded DNS

Abusing Backup Operators Group

WUT IS DIS ?: If we manage to compromise a user account that is member of the Backup Operators group, we can then abuse it's SeBackupPrivilege to create a shadow copy of the current state of the DC, extract the ntds.dit database file, dump the hashes and escalate our privileges to DA.

  1. Once we have access on an account that has the SeBackupPrivilege we can access the DC and create a shadow copy using the signed binary diskshadow:

  1. Next we need to access the shadow copy, we may have the SeBackupPrivilege but we cant just simply copy-paste ntds.dit, we need to mimic a backup software and use Win32 API calls to copy it on an accessible folder. For this we are going to use this amazing repo:

  1. Using smbclient.py from impacket or some other tool we copy ntds.dit and the SYSTEM hive on our local machine.

  2. Use secretsdump.py from impacket and dump the hashes.

  3. Use psexec or another tool of your choice to PTH and get Domain Admin access.

Abusing Exchange

Weaponizing Printer Bug

Abusing ACLs

Abusing IPv6 with mitm6

SID History Abuse

WUT IS DIS?: If we manage to compromise a child domain of a forest and SID filtering isn't enabled (most of the times is not), we can abuse it to privilege escalate to Domain Administrator of the root domain of the forest. This is possible because of the SID History field on a kerberos TGT ticket, that defines the "extra" security groups and privileges.

Exploitation example:

Detailed Articles:

Exploiting SharePoint

Zerologon Exploit

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