Disregard Microsoft SmartScreen Warnings during Installation
While installing Yosemite Server Backup with the current version of Internet Explorer, you might receive a message about the installer’s having failed a hash verification. This message erroneously indicates that the file has been tampered with. In addition, if you are trying to launch the installer using Windows 8 and newer, you will receive a SmartScreen warning banner when trying to launch the installer, regardless of the browser used to download it.
It is okay to disregard these warnings. Downloads provided from the Barracuda Networks website are signed appropriately and the signatures are validated by the Windows operating system.
Microsoft SmartScreen is a reputation-based malware filter used by Windows 8 and newer. It uses several methods to determine whether an executable file is trusted. Files with proper cryptographic signatures might not be marked as trusted.
The most important factor in SmartScreen’s decision to warn a user about an executable appears to be how widely downloaded it is by Internet Explorer users. In addition, updated versions of an executable cannot carry over their trusted reputation from a previous version, since the files do not match. This means that every time an updated binary is released, it essentially starts its reputation from scratch. Even files from legitimate companies cannot carry their trusted reputations forward.
To reiterate, be assured that Yosemite Server Backup files have not been tampered with and contain valid cryptographic signatures. Refer to the following Microsoft documentation for further information on this topic.
References:
http://windows.microsoft.com/en-us/windows7/smartscreen-filter-frequently-asked-questions-ie9