I previously killed a pillager group and their leader and got the bad omen effect. I then went to an igloo and a raid started. I was not near any villages, however in the igloo was the 2 villagers from curing the zombie. I'm not sure but I think that this can happen with other structures that contain villagers.
MC-149875
An igloo is recognized as a village, making it a plausible place for a raid to start
Resolved
Invalid
5
This is most likely a cause of how villages are established. The game looks for villagers, beds, workstations ect. to see if its a village. The problem is, with my testing, all it takes is 1 workstation, a bed, and villager to constitute a "village". Useful for creating raid farms, not so useful for other things. Never the less, still a bug that Mojang overlooked with the igloos.