Islam is considered a religion and not a cult. And yet everything we think of instinctively when we think of the word ‘cult’ is embodied in Islam, times a million.
So in a sense, there is no objective criteria beyond number of adherents and time on earth. Once you’re established, you’re a religion, no matter how sick and evil your practices are.
I understand that Islam was a mixture of a bit of Judaism & a touch of Christianity with the tribal religion of Mohammed.
In that regard, it would originally have been a cult of that religion...whatever it was.