How to Block Threats in File Uploads in Javascript

File upload attacks have arisen as a major attack vector this year, with record numbers of sites falling victim. Having a proper means of defense is crucial if you are to avoid a similar fate. Unfortunately, there are so many methods available to attackers, you are going to need something advanced. Today I’m going to show you how to set up a virus scanning API that allows for advanced threat detection, including executables, scripts, and more.

To begin with, we will need to import the client:

<script src="https://cdn.cloudmersive.com/jsclient/cloudmersive-virus-client.js"></script>

Now we will proceed to call scanFileAdvanced. By default, this will block executables, invalid files, password protected files, and scripts, along with highly sensitive virus scanning. You can also optionally restrict your input to only specific file types. It is recommended that you store the file in memory while the scan is being performed.

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';
// Uncomment the following line to set a prefix for the API key, e.g. "Token" (defaults to null)
//Apikey.apiKeyPrefix = 'Token';
var apiInstance = new CloudmersiveVirusApiClient.ScanApi();
var inputFile = "/path/to/file.txt"; // 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, Pythong 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).
'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);

And there you have it, you now have advanced security for your file uploads.