@deafsilencer: I can't reproduce that warning in my Chrome/Ubuntu. Did you download the package from b2evolution.net or github.com? Do you get the same warning when download a different version using the same computer/browser?

I found some info related with the mime types of the file, but it seems to be correct in our case.

Please watch the video ... I can not express or say more truthful than this video.

https://www.youtube.com/watch?v=VZCPot3Bs-w

You asked this : Do you get the same warning when download a different version using the same computer/browser?

It did never happens before until yesterday that I downloaded 6.6.1 Stable from b2evolution.net ... I just downloaded and tested those older version all the way down to 5.2.2 ... yes, I still get that warning but I did not get warning for downloading other software/files like voidtools.com 's Everything, etc etc ... I always use virustotal.com (58 anti-virus programs in 1 scanner) to check the files for virus before I execute or install it ... all of those files are clean ... odd, isn't it ?