ssonsvr.exe is a part of the Citrix MetaFrame Client remote administration tool. This forms an important part in initiating a terminal service using this product and should not be deleted unless causing problems.
Non-system processes like ssonsvr.exe originate from software you installed on your system. Since most applications store data in your system's registry, it is likely that over time your registry suffers fragmentation and accumulates invalid entries which can affect your PC's performance. It is recommended that you check your registry to identify slowdown issues