@briankrebs I only had that (the secure boot fail) problem if you click the skip windows login procedure. Or how ever its was called. (Last time i used it was years ago). then rufus modified the iso to skip the annoying install process which broke secure boot. Last time i used it without that option the image was valid with secure boot. and also never had any "want to download stuff" requests on my whitelist firewall. but may be outdated info. also i never used the installer only portable version. (it never tried any network-connection. nor did it spawn weird new processes/services.)

i'm pretty sure the "official" download was sourceforge at that time.