Yes, this is/can be a false positive.
I have process explorer from sysinternals installed, and set to replace task manager on my machines, I have downloaded only from microsoft technet, and even old versions of process explorer are tripping the new "Crypt.InfectRansom++" detection.
The installation (manual) directory I have used is: C:\Program Files\ProcessExplorer\ .
I understand the severity of this, if it weren't a benign program, and PE for having a fast update track, would almost be impossible to avoid. So the mistaken identity is completely understood (I am the author of ZB Block, and I know all about false positives... headaches.)
The question is, what can be done?
Zap