bumper.php

<?php

date_default_timezone_set('Asia/Vladivostok');

$_config = (object)[
    'username' => 'getjump',
    'password' => 'pw',
    'forum' => 'http://www.sythe.org/',
    'thread_id' => '1824569',
    'message' => 'Or add on steam: jerbos41',
    'randomiseMessage' => true
];

$_randomVariants = [
    ' /5chars',
    ' ghe.',
    ''
];

$_data = [
    'vb_login_username' => $_config->username,
    'vb_login_password' => '',
    's' => '',
    'cookieuser' => '1',
    'do' => 'login',
    'vb_login_md5password' => md5($_config->password),
    'vb_login_md5password_utf' => md5($_config->password)
];

$_options = [
    'http' => [
        'method' => 'POST',
        'header' => "Content-Type: application/x-www-form-urlencoded\r\n",
        'content' => http_build_query($_data)
    ]
];

$_context = stream_context_create($_options);
$result = file_get_contents($_config->forum . 'login.php?do=login', false, $_context);

$headers = implode("\n", $http_response_header);
preg_match_all('/(bb\S+)=(\S+);/i', $headers, $matches);
$_auth = array_combine($matches[1], $matches[2]);

debug_output('Auth as user_id = ' . $_auth['bbuserid'] . ' successful');

$_post_data = [
    'ajax' => '1',
    'ajax_lastpost' => '1441597118', // WTF?
    'message' => $_config->message,
    'wysiwyg' => 0,
    'styleid' => 0,
    'fromquickreply' => 1,
    's' => '',
    'do' => 'postreply',
    't' => $_config->thread_id,
    'p' => 'who cares',
    'parseurl' => '1',
    'loggedinuser' => $_auth['bbuserid'],
];

if($_config->randomiseMessage)
{
    $_post_data['message'] .= $_randomVariants[rand(0, count($_randomVariants))];
}

$_post_options = [
    'http' => [
        'method' => 'POST',
        'header' =>
            "Content-Type: application/x-www-form-urlencoded\r\n" .
            "Cookie: " . http_build_query($_auth, '', '; '),
        'content' => http_build_query($_post_data)
    ]
];

$_post_context = stream_context_create($_post_options);

$result = file_get_contents($_config->forum . 'newreply.php?do=postreply&t=' . $_config->thread_id, false, $_post_context);

if(preg_match('/' . $_post_data['message'] . '/iu', $result))
{
    debug_output('Message \''. $_post_data['message']  .'\' was sent successfully');
}

function debug_output($message)
{
    print '[Bumper] ' . date('H:i:s') . ':    ' . $message . PHP_EOL;
}