Check file hashes (sha256) with VirusTotal - no file uploads, no telemetry.
Faster checks because no file upload is required
The purpose of this extension is to make sure NO SENSITIVE DATA is being uploaded to virustotal.com
Autochecks downloaded files. (experimental, expect inconsistencies). So far if the file is small or is downloaded immediately, this autocheck works fine.
Otherwise, you can drag and drop the file from the downloads icon into "Upload and Scan File"
Use this to inspect the extension's code on this page for additional verification: Extension Inspector