bulk-user-addition.ps1

 # ----- Edit these Variables for your own Use Case ----- #
$PASSWORD_FOR_USERS   = "Password1"
$NUMBER_OF_ACCOUNTS_TO_CREATE = 10000
# ------------------------------------------------------ #

Function generate-random-name() {
    $consonants = @('b','c','d','f','g','h','j','k','l','m','n','p','q','r','s','t','v','w','x','z')
    $vowels = @('a','e','i','o','u','y')
    $nameLength = Get-Random -Minimum 3 -Maximum 7
    $count = 0
    $name = ""

    while ($count -lt $nameLength) {
        if ($($count % 2) -eq 0) {
            $name += $consonants[$(Get-Random -Minimum 0 -Maximum $($consonants.Count - 1))]
        }
        else {
            $name += $vowels[$(Get-Random -Minimum 0 -Maximum $($vowels.Count - 1))]
        }
        $count++
    }

    $name

}

$count = 1

New-ADOrganizationalUnit -Name _USERS -ProtectedFromAccidentalDeletion $false

while ($count -lt $NUMBER_OF_ACCOUNTS_TO_CREATE) {
    $firstname = generate-random-name
    $lastName = generate-random-name
    $username = $firstname + '.' + $lastName
    $password = ConvertTo-SecureString $PASSWORD_FOR_USERS -AsPlainText -Force

    Write-Host "[+] Creating Username:Password = $($username):'$($PASSWORD_FOR_USERS)'" -ForegroundColor Green
    
    New-AdUser -AccountPassword $password `
               -GivenName $first `
               -Surname $last `
               -DisplayName $username `
               -Name $username `
               -EmployeeID $username `
               -PasswordNeverExpires $true `
               -Path "ou=_USERS,$(([ADSI]`"").distinguishedName)" `
               -Enabled $true
    $count++
}