I've released vagrant-spk 1.1.1, which solely updates our Windows build and installer. I would strongly encourage Windows users update to this release. In the process of updating the Windows build dependencies, I spent a little bit of attention on the fact that vagrant-spk for Windows includes ssh.exe, particularly for the sake of enabling "vagrant-spk vm ssh".
We were pulling this from a 2015 release of MSysGit, which is now known as the Git for Windows SDK. As it turns out, we do not need to do this, because recent versions of Vagrant for Windows, which vagrant-spk requires, includes ssh.exe and will use it's own if there isn't an ssh.exe in the system's PATH.
In my personal case, I had the Windows Optional Feature of the OpenSSH Client installed, so my vagrant-spk was using that version, provided by Microsoft, which was also in my PATH. However, I am mildly concerned about the fact that vagrant-spk for Windows puts its ssh.exe in the Windows system's PATH, and it's a 2015 copy of ssh.exe. Depending on the order of your PATH and whether or not you use a different application which looks for ssh.exe in your PATH, vagrant-spk could theoretically be providing you a 2015 version of ssh.exe when you are using other applications, which makes me unhappy.
The vagrant-spk 1.1.1 installer no longer includes ssh.exe, and will delete it from the vagrant-spk program folder.