Hello @ and welcome to the Webroot Community.

 

The file will be scanned immediately upon downloading, but I'd recommend using our Filtering Extension to determine whether a site is trustworthy or not to download from.

 

Example:

 

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To scan the file befored download would put a huge processing / internet bandwidth load on the Webroot servers. Just imagine all the files from all the users across the world all day long having to go to Webroot first then to the client. It would effect the client by slowing down the time to get a file to almost double in the worst case. I cannot see this a viable option.

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