The following files are now available for testing from alpha.gnu.org in
the directory gnu/octave
-rw-r--r-- 32508461 Aug 26 19:54 octave-6.0.90.tar.gz
-rw-r--r-- 21424489 Aug 26 19:54 octave-6.0.90.tar.lz
-rw-r--r-- 25050816 Aug 26 19:55 octave-6.0.90.tar.xz
-rw-r--r-- 352766877 Aug 27 13:21 octave-6.0.90-w64-installer.exe
-rw-r--r-- 341029732 Aug 27 13:25 octave-6.0.90-w64.7z
-rw-r--r-- 586445094 Aug 27 13:31 octave-6.0.90-w64.zip
All three of the windows versions (before packages were added) at least pass a Windows Defender malware check both before and after extracting/installing. I haven't VirusTotal tested anything for false positives yet.