There is a recent thread that mentions this update and a fix for a clock issue from the TCU. Otherwise, this appears to be the latest version for your system. The files for this Sync application are .VBF format and are not loaded thru the Sync 3 update process, instead are updated like firmware updates to the modules.
Sync 2.5 bug - Ford Focus Club - Ford Owners Club - Ford Forums
See this thread here for more…
Is upgrading to 3.4 possible? (Sync 2.5) - Ford / Sync 3 - CyanLabs Official Community