How to Block File Uploads Containing Scripts using PHP

Malicious scripts are often embedded within file uploads and used to exploit weakly configured file upload processes, so it’s vitally important to implement rigorous security policies against them. The free-to-use Virus Scan API provided in this article provides in-depth content verification services, automatically detecting scripts within files and allowing you to block these files by setting a simple request parameter — allowScripts — to “false”. The underlying service simultaneously scans files for viruses and malware, referencing a growing list of more than 17 million virus and malware signatures in the process.

You can take advantage of this API in a few quick steps using ready-to-run PHP code examples. To install the PHP SDK, first run the following command:

composer require cloudmersive/cloudmersive_virusscan_api_client

After that, copy the below code to structure your API call:

<?php
require_once(__DIR__ . '/vendor/autoload.php');

// Configure API key authorization: Apikey
$config = Swagger\Client\Configuration::getDefaultConfiguration()->setApiKey('Apikey', 'YOUR_API_KEY');



$apiInstance = new Swagger\Client\Api\ScanApi(
    
    
    new GuzzleHttp\Client(),
    $config
);
$input_file = "/path/to/inputfile"; // \SplFileObject | Input file to perform the operation on.
$allow_executables = true; // bool | Set to false to block executable files (program code) from being allowed in the input file.  Default is false (recommended).
$allow_invalid_files = true; // bool | Set to false to block invalid files, such as a PDF file that is not really a valid PDF file, or a Word Document that is not a valid Word Document.  Default is false (recommended).
$allow_scripts = true; // bool | Set to false to block script files, such as a PHP files, Python scripts, and other malicious content or security threats that can be embedded in the file.  Set to true to allow these file types.  Default is false (recommended).
$allow_password_protected_files = true; // bool | Set to false to block password protected and encrypted files, such as encrypted zip and rar files, and other files that seek to circumvent scanning through passwords.  Set to true to allow these file types.  Default is false (recommended).
$allow_macros = true; // bool | Set to false to block macros and other threats embedded in document files, such as Word, Excel and PowerPoint embedded Macros, and other files that contain embedded content threats.  Set to true to allow these file types.  Default is false (recommended).
$allow_xml_external_entities = true; // bool | Set to false to block XML External Entities and other threats embedded in XML files, and other files that contain embedded content threats.  Set to true to allow these file types.  Default is false (recommended).
$allow_insecure_deserialization = true; // bool | Set to false to block Insecure Deserialization and other threats embedded in JSON and other object serialization files, and other files that contain embedded content threats.  Set to true to allow these file types.  Default is false (recommended).
$allow_html = true; // bool | Set to false to block HTML input in the top level file; HTML can contain XSS, scripts, local file accesses and other threats.  Set to true to allow these file types.  Default is false (recommended) [for API keys created prior to the release of this feature default is true for backward compatability].
$restrict_file_types = "restrict_file_types_example"; // string | Specify a restricted set of file formats to allow as clean as a comma-separated list of file formats, such as .pdf,.docx,.png would allow only PDF, PNG and Word document files.  All files must pass content verification against this list of file formats, if they do not, then the result will be returned as CleanResult=false.  Set restrictFileTypes parameter to null or empty string to disable; default is disabled.

try {
    $result = $apiInstance->scanFileAdvanced($input_file, $allow_executables, $allow_invalid_files, $allow_scripts, $allow_password_protected_files, $allow_macros, $allow_xml_external_entities, $allow_insecure_deserialization, $allow_html, $restrict_file_types);
    print_r($result);
} catch (Exception $e) {
    echo 'Exception when calling ScanApi->scanFileAdvanced: ', $e->getMessage(), PHP_EOL;
}
?>

Now you can set custom policies against files containing scripts and a variety of other non-malware content threat types. To authenticate your API request, copy the API key from your free-tier Cloudmersive account into the $config parameter above.