Any of the following 64-bit multi-core processor servers:
Windows Server 2008 R2
Windows Server 2012
Windows Server 2012 R2
Minimum of 16 GB RAM
Depending on the size and frequency of your scans, this amount might need to be significantly increased.
Minimum 3 GB disk space
This number is only taking into consideration the database engine and the client components.
NOTE:For more details on SQL Server hardware requirements, see https://msdn.microsoft.com/en-us/library/ms143506.aspx.