First time playing throught Xenonauts for my twitch channel.
This is my 4th stream of this game, liking the game a lot.
So I was about to start a mission on a shot down landing craft or something, I don't remember right now.
As soon as the mission loaded I did what I always do and save the game under a "landed" save game slot.
During or right after the saving process, the game crashed. I got a message from Malware Bytes Premium that the xenonauts.exe was blocked after detected some generic ransomware threat.

Now the game doesn't start.

I highly doubt the game (offline installer) was infected, but for obvious reasons I am worried.
I checked the exe again (right click, check with malware bytes, and found nothing).

I am worried what if the exe was somehow infected by something else and I am having this problem.
Or of course if everything is definitely safe.

Any suggestions?

What you could do is back up your savegames, uninstall the game, delete the folder and all traces of it on your system and reïnstall and see if it comes back.
Still might be a false positive but just to be safe.

Weird.
Check Virustotal if you can.