Mine did this from the first time I installed rootsh. I have no idea what that password is supposed to be. I was able to reset it by editing the passwd- (or passwd? I don't remember. It was stored somewhere as some random mix of masked characters. I just edited them, saved the file, and I think it got encypted/masked when I looked at it again, but yeah) file as root though, before my reflash. Haven't gotten around to it after my reflash.

I THINK that it asking for a password is the normal behavior for "sudo" - I do not think that it's supposed to randomly set one without you being asked to set one though. There should also be a way to reset it, I just don't know what that way is.

BTW, I just tested rootsh - and that comes up with a "deprecated" message. Sudo on the other hand still works, it just asks for a password each time. *Shrug*