VirusTotal is a useful online virus scanning service owned by Google since 2012. The developers of the service have developed the VT4Browsers plugin for browsers Firefox and Google Chrome.
VT4Browsers automatically submits certain file downloads to Google's VirusTotal scan service. You can then click on a link displayed by the extension to open the scan results on the VirusTotal site.
The extension submits files that you download from the web with the exception of the document file types by default. However, you can change the default behavior of the extension from the settings.
The settings are divided into a public part for the general public and a section reserved for users who have one key API. Adding the API to the extension unlocks advanced functions.
You can read more in the support article of VirusTotal that provides additional information on all new options.
As mentioned above, the VT4Browsers add-on is available for Chrome and Firefox.
But most Google Chromium-based browsers work just fine with the extension.
You can try the extension on browser you use and let us know in the comments.