Script Powershell para alterar a senha do administrador local

Question

Eu tenho um script que estou usando para alterar a senha do administrador local da Microsoft. O link é o local onde o encontrei. Aqui está o script para qualquer um com preguiça de clicar:

function Invoke-PasswordRoll
{
<#
.SYNOPSIS

This script can be used to set the local account passwords on remote machines to random passwords. The 

username/password/server combination will be saved in a CSV file.
The account passwords stored in the CSV file can be encrypted using a password of the administrators choosing to 

ensure clear-text account passwords aren't written to disk.
The encrypted passwords can be decrypted using another function in this file: ConvertTo-CleartextPassword


Function: Invoke-PasswordRoll
Author: Microsoft
Version: 1.0

.DESCRIPTION

This script can be used to set the local account passwords on remote machines to random passwords. The 

username/password/server combination will be saved in a CSV file.
The account passwords stored in the CSV file can be encrypted using a password of the administrators choosing to 

ensure clear-text account passwords aren't written to disk.
The encrypted passwords can be decrypted using another function in this file: ConvertTo-CleartextPassword

.PARAMETER ComputerName

An array of computers to run the script against using PowerShell remoting.

.PARAMETER LocalAccounts

An array of local accounts whose password should be changed.

.PARAMETER TsvFileName

The file to output the username/password/server combinations to.

.PARAMETER EncryptionKey

A password to encrypt the TSV file with. Uses AES encryption. Only the passwords stored in the TSV file will be 

encrypted, the username and servername will be clear-text.

.PARAMETER PasswordLength

The length of the passwords which will be randomly generated for local accounts.

.PARAMETER NoEncryption

Do not encrypt the account passwords stored in the TSV file. This will result in clear-text passwords being 

written to disk.

.EXAMPLE

. .\Invoke-PasswordRoll.ps1    #Loads the functions in this script file
Invoke-PasswordRoll -ComputerName (Get-Content computerlist.txt) -LocalAccounts @

("administrator","CustomLocalAdmin") -TsvFileName "LocalAdminCredentials.tsv" -EncryptionKey "Password1"

Connects to all the computers stored in the file "computerlist.txt". If the local account "administrator" and/or 

"CustomLocalAdmin" are present on the system, their password is changed
to a randomly generated password of length 20 (the default). The username/password/server combinations are 

stored in LocalAdminCredentials.tsv, and the account passwords are AES encrypted using the password "Password1".

.EXAMPLE

. .\Invoke-PasswordRoll.ps1    #Loads the functions in this script file
Invoke-PasswordRoll -ComputerName (Get-Content computerlist.txt) -LocalAccounts @("administrator") -TsvFileName 

"LocalAdminCredentials.tsv" -NoEncryption -PasswordLength 40

Connects to all the computers stored in the file "computerlist.txt". If the local account "administrator" is 

present on the system, its password is changed to a random generated
password of length 40. The username/password/server combinations are stored in LocalAdminCredentials.tsv 

unencrypted.

.NOTES
Requirements: 
-PowerShellv2 or above must be installed
-PowerShell remoting must be enabled on all systems the script will be run against

Script behavior:
-If a local account is present on the system, but not specified in the LocalAccounts parameter, the script will 

write a warning to the screen to alert you to the presence of this local account. The script will continue 

running when this happens.
-If a local account is specified in the LocalAccounts parameter, but the account does not exist on the computer, 

nothing will happen (an account will NOT be created).
-The function ConvertTo-CleartextPassword, contained in this file, can be used to decrypt passwords that are 

stored encrypted in the TSV file.
-If a server specified in ComputerName cannot be connected to, PowerShell will output an error message.
-Microsoft advises companies to regularly roll all local and domain account passwords.

#>
    [CmdletBinding(DefaultParameterSetName="Encryption")]
    Param(
        [Parameter(Mandatory=$true)]
        [String[]]
        $ComputerName,

        [Parameter(Mandatory=$true)]
        [String[]]
        $LocalAccounts,

        [Parameter(Mandatory=$true)]
        [String]
        $TsvFileName,

        [Parameter(ParameterSetName="Encryption", Mandatory=$true)]
        [String]
        $EncryptionKey,

        [Parameter()]
        [ValidateRange(20,120)]
        [Int]
        $PasswordLength = 20,

        [Parameter(ParameterSetName="NoEncryption", Mandatory=$true)]
        [Switch]
        $NoEncryption
    )


    #Load any needed .net classes
    Add-Type -AssemblyName "System.Web" -ErrorAction Stop


    #This is the scriptblock that will be executed on every computer specified in ComputerName
    $RemoteRollScript = {
        Param(
            [Parameter(Mandatory=$true, Position=1)]
            [String[]]
            $Passwords,

            [Parameter(Mandatory=$true, Position=2)]
            [String[]]
            $LocalAccounts,

            #This is here so I can record what the server name that the script connected to was, sometimes the 

DNS records get messed up, it can be nice to have this.
            [Parameter(Mandatory=$true, Position=3)]
            [String]
            $TargettedServerName
        )

        $LocalUsers = Get-WmiObject Win32_UserAccount -Filter "LocalAccount=true" | Foreach {$_.Name}

        #Check if the computer has any local user accounts whose passwords are not going to be rolled by this 

script
        foreach ($User in $LocalUsers)
        {
            if ($LocalAccounts -inotcontains $User)
            {
                Write-Warning "Server: '$($TargettedServerName)' has a local account '$($User)' whos password is 

NOT being changed by this script"
            }
        }

        #For every local account specified that exists on this server, change the password
        $PasswordIndex = 0
        foreach ($LocalAdmin in $LocalAccounts)
        {
            $Password = $Passwords[$PasswordIndex]

            if ($LocalUsers -icontains $LocalAdmin)
            {
                try
                {
                    $objUser = [ADSI]"WinNT://localhost/$($LocalAdmin), user"
                    $objUser.psbase.Invoke("SetPassword", $Password)

                    $Properties = @{
                        TargettedServerName = $TargettedServerName
                        Username =  $LocalAdmin
                        Password = $Password
                        RealServerName = $env:computername
                    }

                    $ReturnData = New-Object PSObject -Property $Properties
                    Write-Output $ReturnData
                }
                catch
                {
                    Write-Error "Error changing password for user:$($LocalAdmin) on server:

$($TargettedServerName)"
                }
            }

            $PasswordIndex++
        }
    }


    #Generate the password on the client running this script, not on the remote machine. System.Web.Security 

isn't available in the .NET Client profile. Making this call
    #    on the client running the script ensures only 1 computer needs the full .NET runtime installed (as 

opposed to every system having the password rolled).
    function Create-RandomPassword
    {
        Param(
            [Parameter(Mandatory=$true)]
            [ValidateRange(20,120)]
            [Int]
            $PasswordLength
        )

        $Password = [System.Web.Security.Membership]::GeneratePassword($PasswordLength, $PasswordLength / 4)

        #This should never fail, but I'm putting a sanity check here anyways
        if ($Password.Length -ne $PasswordLength)
        {
            throw new Exception("Password returned by GeneratePassword is not the same length as required. 

Required length: $($PasswordLength). Generated length: $($Password.Length)")
        }

        return $Password
    }


    #Main functionality - Generate a password and remote in to machines to change the password of local accounts 

specified
    if ($PsCmdlet.ParameterSetName -ieq "Encryption")
    {
        try
        {
            $Sha256 = new-object System.Security.Cryptography.SHA256CryptoServiceProvider
            $SecureStringKey = $Sha256.ComputeHash([System.Text.UnicodeEncoding]::Unicode.GetBytes

($EncryptionKey))
        }
        catch
        {
            Write-Error "Error creating TSV encryption key" -ErrorAction Stop
        }
    }

    foreach ($Computer in $ComputerName)
    {
        #Need to generate 1 password for each account that could be changed
        $Passwords = @()
        for ($i = 0; $i -lt $LocalAccounts.Length; $i++)
        {
            $Passwords += Create-RandomPassword -PasswordLength $PasswordLength
        }

        Write-Output "Connecting to server '$($Computer)' to roll specified local admin passwords"
        $Result = Invoke-Command -ScriptBlock $RemoteRollScript -ArgumentList @($Passwords, $LocalAccounts, 

$Computer) -ComputerName $Computer
        #If encryption is being used, encrypt the password with the user supplied key prior to writing to disk
        if ($Result -ne $null)
        {
            if ($PsCmdlet.ParameterSetName -ieq "NoEncryption")
            {
                $Result | Select-Object Username,Password,TargettedServerName,RealServerName | Export-Csv -

Append -Path $TsvFileName -NoTypeInformation
            }
            else
            {
                #Filters out $null entries returned
                $Result = $Result | Select-Object Username,Password,TargettedServerName,RealServerName

                foreach ($Record in $Result)
                {
                    $PasswordSecureString = ConvertTo-SecureString -AsPlainText -Force -String 

($Record.Password)
                    $Record | Add-Member -MemberType NoteProperty -Name EncryptedPassword -Value (ConvertFrom-

SecureString -Key $SecureStringKey -SecureString $PasswordSecureString)
                    $Record.PSObject.Properties.Remove("Password")
                    $Record | Select-Object Username,EncryptedPassword,TargettedServerName,RealServerName | 

Export-Csv -Append -Path $TsvFileName -NoTypeInformation
                }
            }
        }
    }
}


function ConvertTo-CleartextPassword
{
<#
.SYNOPSIS
This function can be used to decrypt passwords that were stored encrypted by the function Invoke-PasswordRoll.

Function: ConvertTo-CleartextPassword
Author: Microsoft
Version: 1.0

.DESCRIPTION
This function can be used to decrypt passwords that were stored encrypted by the function Invoke-PasswordRoll.


.PARAMETER EncryptedPassword

The encrypted password that was stored in a TSV file.

.PARAMETER EncryptionKey

The password used to do the encryption.


.EXAMPLE

. .\Invoke-PasswordRoll.ps1    #Loads the functions in this script file
ConvertTo-CleartextPassword -EncryptionKey "Password1" -EncryptedPassword 

76492d1116743f0423413b16050a5345MgB8AGcAZgBaAHUAaQBwADAAQgB2AGgAcABNADMASwBaAFoAQQBzADEAeABjAEEAPQA9AHwAZgBiAGYA

MAA1ADYANgA2ADEANwBkADQAZgAwADMANABjAGUAZQAxAGIAMABiADkANgBiADkAMAA4ADcANwBhADMAYQA3AGYAOABkADcAMQA5ADQAMwBmAGYA

NQBhADEAYQBjADcANABkADIANgBhADUANwBlADgAMAAyADQANgA1ADIAOQA0AGMAZQA0ADEAMwAzADcANQAyADUANAAzADYAMAA1AGEANgAzADEA

MQA5ADAAYwBmADQAZAA2AGQA"

Decrypts the encrypted password which was stored in the TSV file.

#>
    Param(
        [Parameter(Mandatory=$true)]
        [String]
        $EncryptedPassword,

        [Parameter(Mandatory=$true)]
        [String]
        $EncryptionKey
    )

    $Sha256 = new-object System.Security.Cryptography.SHA256CryptoServiceProvider
    $SecureStringKey = $Sha256.ComputeHash([System.Text.UnicodeEncoding]::Unicode.GetBytes($EncryptionKey))

    [SecureString]$SecureStringPassword = ConvertTo-SecureString -String $EncryptedPassword -Key 

$SecureStringKey
    Write-Output ([System.Runtime.InteropServices.Marshal]::PtrToStringAuto

([System.Runtime.InteropServices.Marshal]::SecureStringToCoTaskMemUnicode($SecureStringPassword)))
}

Quando executo o script usando:

Invoke-PasswordRoll -ComputerName (Get-Content computerlist.txt) -LocalAccounts @("administrator","CustomLocalAdmin") -TsvFileName "LocalAdminCredentials.tsv" -EncryptionKey "Password1"

altera a senha nos computadores de destino, mas não a altera para "Password1". O que exatamente esse script está fazendo?

    

Answer 1

Como Tomasz e Zoredache disseram: o script que a Microsoft fornece só pode ser usado para definir senhas de contas locais em máquinas remotas para senhas aleatórias. As senhas de conta armazenadas no arquivo CSV podem ser criptografadas usando uma senha dos administradores que escolhem (o parâmetro -EncryptionKey ) para garantir que as senhas de conta com texto não criptografado não sejam gravadas no disco.

As senhas criptografadas (armazenadas no arquivo TSV) podem ser descriptografadas usando outra função no mesmo arquivo: ConvertTo-CleartextPassword.

Em nosso ambiente, também gostaríamos de alterar a senha regularmente, então criamos dois scripts: um para criar um novo arquivo com uma senha criptografada (de nossa própria escolha) e distribuímos esse arquivo para todas as nossas estações de trabalho. Um script de segundos (distribuído também para as estações de trabalho) é executado a cada X horas e redefine a senha com base no conteúdo do arquivo. É claro que a senha usada para criptografar e descriptografar ainda é armazenada em texto simples, mas a senha em si não é. Dessa forma, você realmente precisa saber o que está fazendo para recuperar a senha do administrador local, pois o arquivo de criptografia e o script são salvos em locais diferentes, o que é bastante seguro.

Crie o arquivo de senha

Usamos o seguinte script (removemos o registro de erros e as tentativas / capturas) para criar um arquivo de senha:

$LocalAdminPW = "0urAdminP@ssword" #the password that is used to set as the local admin password
$EncryptionPW = "0urEncryptionP@ssword" #password to encrypt and decrypt the password
$File = "C:\Temp\Password.tsv" #file to create

#Create encryption key
$Sha256 = new-object System.Security.Cryptography.SHA256CryptoServiceProvider
$SecureStringKey = $Sha256.ComputeHash([System.Text.UnicodeEncoding]::Unicode.GetBytes($EncryptionPW))

#Encrypt the password with the user supplied encryption password
PasswordSecureString = ConvertTo-SecureString -AsPlainText -Force -String $LocalAdminPW

#Create TSV-File with the encrypted password
ConvertFrom-SecureString -Key $SecureStringKey -SecureString $PasswordSecureString | Out-File -Force -FilePath "$File"

#Gathering the new encrypted password for the local administrator account
$LocalAdminPW = Get-Content $FileLocation

Defina a Senha do administrador local com o arquivo de senha criado

Usamos o seguinte script para descriptografar a senha do arquivo de senha e usá-la para definir a senha do Administrador (limpei o tratamento e o registro de erros):

#function to get decrypted password
Function Get-DecryptedPassword {
    [CmdletBinding()]
    param(
        $EncryptedPW,
        $LocalAdminPW
    )

    #Decrypt the password with the user supplied encryption password
    $Sha256 = new-object System.Security.Cryptography.SHA256CryptoServiceProvider
    $SecureStringKey = $Sha256.ComputeHash([System.Text.UnicodeEncoding]::Unicode.GetBytes($EncryptionPW))
    [SecureString]$SecureStringPassword = ConvertTo-SecureString -String $LocalAdminPW -Key $SecureStringKey
    return ([System.Runtime.InteropServices.Marshal]::PtrToStringAuto([System.Runtime.InteropServices.Marshal]::SecureStringToCoTaskMemUnicode($SecureStringPassword)))
}

#Change password local admin account
$LocalAdmin = "Administrator"
$objUser = [ADSI]"WinNT://localhost/$($LocalAdmin), user"
$objUser.psbase.Invoke("SetPassword", (Get-DecryptedPassword -EncryptedPW $EncryptionPW  -LocalAdminPW $LocalAdminPW))

    

Answer 2

Armazenar a senha em uma planilha não é ideal e configurar todas as suas máquinas para a mesma senha é um outro problema no roubo de credenciais (mesmo se você alterá-la regularmente). A ferramenta LAPS pode ser usada para randomizar com segurança senhas de administradores locais. Se você estiver tentando resolver os problemas no artigo, considere o uso de uma credencial de domínio. Se você está simplesmente tentando alterar as senhas, use a ferramenta LAPS ( link )

    

Answer 3

Basta ler os comentários no script colado:

Se a conta local "administrator" e / ou "CustomLocalAdmin" estiverem presentes no sistema, sua senha será alterada para uma senha gerada aleatoriamente de comprimento 20 (o padrão).

As combinações de nome de usuário / senha / servidor são armazenadas em LocalAdminCredentials.tsv e as senhas da conta são criptografadas AES usando a senha "Password1".