OSX System Workbench for STM32 installer is corrupt
This helped me, thanks
When downloading with Firefox and issuing "open installer_sw4stm32_macos_64bits.app", a long lasting verification is done by OS X and then a message appears telling that the application is corrupted and should be moved to trash.
When downloading with wget, "open ..." doesn't trigger the verification and installer simply runs.
So success, however someone should resolve why the verification fails