Notice that WeChat updated its login process verification from new device that it did not know for the user.
Now they will present you with some headshots for you to pick 2 from the list, then contact names, and one additional test to MAKE SURE that it is you. It really helps to screen out phony login if it was not you.
Bravo for the work that they did, I feel quite secure now.
Mind you from a known device, just the password will do.
Of course, first signup to WeChat will be so, then how long will it take you to the next device? At least one dead battery later, right? One day grace period.