Extension allows you to compare your files directly in Firefox. Just click on toolbar icon. Also you will get sha-256 hash of files.
Also your can check file hash on viruses or find native file-name with VirusTotal service.

Files Comparison and Virus Check - Firefox Add-on
Files Comparison and Virus Check is a Firefox add-on that enables you to compare files, obtain sha-256 hash, and check for viruses using VirusTotal service. Analyze files directly in Firefox with just a click on the toolbar icon.
Add-on stats
Other platforms
Not available on Chrome
Not available on Android
Not available on Edge
Add-on safety
Risk impact
Files Comparison and virus check requires very minimum permissions.
Risk impact analysis details
- Medium Enables sending notifications which can be spammed but have minimal direct security impact.
- Low ******* ****** ** *** ********* ********
Risk likelihood
Files Comparison and virus check is probably trust-worthy. Prefer other publishers if available. Exercise caution when installing this add-on.
Risk likelihood analysis details
- High This extension has low user count. Unpopular extensions may not be stable or safe.
- Low **** ********* *** ******* **** **** * ****** **** ***** ******** *** **** ****** ** ** ****** *** *****
- Low **** ********* *** ***** **** **** * ****** **** ***** ********** *** **** ****** ** ** ****** *** *****
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