In this specific situation, I doubt that the signal is coming from the guest OS. This scenario can be replicated by issuing a kill from Terminal of the process ID of the vmware-vmx hosting the running VM.
Here I issued sudo kill 4178 from Terminal and the last line in the vmware.log
vmx| W003: Caught signal 15 -- tid 4178 (eip 0x7f966a591db6)
Again, I have no idea why the vmware-vmx process would receive signal 15. You could try using journalctl and look at the timeframes when these signals occurred and it might give a clue where the signal is coming from and possibly why.
