How to Remove Invalid Files from a File Upload Process in Node.js

It goes without saying that we should actively seek out and remove invalid files from our website’s file upload process — but that’s easier said than done. Detecting invalid files requires in-depth content verification measures which look past the file extension and header and investigate the file encoding layer instead. Incorporating file validation and verification on top of additional security checks is a challenge in and of itself, however, and it can result in a slower upload process than we might envision for our application.

The free-to-use API below provides 360 content protection in a single request, checking files for dangerous viruses and malware while additionally providing customizable policies to categorically block invalid file uploads. Using the ready-to-run Node.js code examples provided below, you can take advantage of this API in minutes and make up to 800 free API calls per month with zero additional commitments.

To install the Node.js SDK with npm install, run the below command:

npm install cloudmersive-virus-api-client --save

Alternatively, you can also add the Node client to your package.json:

  "dependencies": {
    "cloudmersive-virus-api-client": "^1.1.9"
  }

With installation out of the way, you can now copy & paste the below code examples to structure your API call. Provide your API key to authenticate your request, and then set the allowInvalidFiles boolean to “False” to block invalid file uploads:

var CloudmersiveVirusApiClient = require('cloudmersive-virus-api-client');
var defaultClient = CloudmersiveVirusApiClient.ApiClient.instance;

// Configure API key authorization: Apikey
var Apikey = defaultClient.authentications['Apikey'];
Apikey.apiKey = 'YOUR API KEY';



var apiInstance = new CloudmersiveVirusApiClient.ScanApi();

var inputFile = Buffer.from(fs.readFileSync("C:\\temp\\inputfile").buffer); // File | Input file to perform the operation on.

var opts = { 
  'allowExecutables': true, // Boolean | Set to false to block executable files (program code) from being allowed in the input file.  Default is false (recommended).
  'allowInvalidFiles': true, // Boolean | 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).
  'allowScripts': true, // Boolean | 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).
  'allowPasswordProtectedFiles': true, // Boolean | 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).
  'allowMacros': true, // Boolean | 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).
  'allowXmlExternalEntities': true, // Boolean | 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).
  'allowInsecureDeserialization': true, // Boolean | 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).
  'allowHtml': true, // Boolean | 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].
  'restrictFileTypes': "restrictFileTypes_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.
};

var callback = function(error, data, response) {
  if (error) {
    console.error(error);
  } else {
    console.log('API called successfully. Returned data: ' + data);
  }
};
apiInstance.scanFileAdvanced(inputFile, opts, callback);

With the Boolean configured to block Invalid Files, any files which fail content verification against their extension will receive a CleanResult: False value in the API response body (the same response provided when a Virus or Malware signature is detected).