I've done some research and it seems this is a false positive for Panda that comes up from time to time on their forums, and it's affecting some of the .exe files. As I keep uploading Dungeonlike in a SFX archive, it's always a different .exe file each time, so maybe I should just do a simple .zip instead, as many people on Itch.io seem to be doing. 

Not sure how up to date your Panda is (it being out of date seems like the only explanation as to why my freshly installed version does not flag any issues while your does), but I see they keep getting posts on their forums about this (bunch of forum posts), then developers submit apps to be whitelisted and that gets updated in next versions.

Anyway, thanks for raising this and for the follow up with details! Got me quite scared there for a second when I realised that I don't perform any scans on these archives before uploading them, so there always was a chance for a virus to tag along. Added a routine antivirus scan to my list of "deployment procedures" I perform before any version is released, just to keep it safer.