First of all the Add-on works on Windows and Linux. While Windows doesn't need any special configuration, on Linux you need to extract and run a .sh, which is open source and does not need root access because it is installed in the user's directory, so I don't think it can cause any damage, that basically installs a bridge between Jdownloader and the browser. The add-on DOES work and is an excellent alternative to IDM for Linux users, it is not a virus.

I dare to say that jDownloader + Download with JDownloader is the only alternative in all Linux to IDM + IDM Integration Module, this extension deserves much more love sincerely.