The javascript that ESET detects are these:
Probably what it uses to insert ads on the free version. Don't quote me on that. The setup.exe isn't something to worry about. The other two "injection.js" are what is inside the setup file which is what ESET don't like. Probably should have looked inside them before resetting VM... oops.
What I do know is that if you delete these files, it has no affect on the operation of the VPN service. At least not with using the "pro" version of it. Using the free version, deleting these might stop ad injections into the web pages.
And to be clear on another thing... there is NO adware or malwae in the installer that you get in the email. Nothing gets installed other than the VPN and the necessary components that most other VPN also use. Manual checking and scans using in depth tools reveal nothing wrong. I'm not using this because I pay for PIA yearly. Nothing should stop anyone else from using it.