guess_encoding.php

<?php
declare(strict_types=1);

function guess_encoding(string $str): string {
    if($str===''){throw new \InvalidArgumentException('input string empty!');}
    $blacklist = array (
            'pass',
            'auto',
            'wchar',
            'byte2be',
            'byte2le',
            'byte4be',
            'byte4le',
            'BASE64',
            'UUENCODE',
            'HTML-ENTITIES',
            '7bit',
            '8bit',
            'Quoted-Printable',
    );
    $encodings = array_diff ( mb_list_encodings (),$blacklist );
    $detected = mb_detect_encoding ( $str, $encodings, true );
    return ( string ) $detected;
}

this is almost certainly UTF16 but is being identifier as UTF8...
hex2bin("570069006e0064006f00770073002000530075006200730079007300740065006d00200066006f00720020004c0069006e0075007800200044006900730074007200690062007500740069006f006e0073003a000d000d000a005500620075006e00740075002d00310036002e003000340020002800440065006600610075006c00740029000d000d000a00");