Those were wights. Undead servants (human or animal) resurrected by the White Walkers.
They are stupid, mindless, they use regular weapons (whatever they were holding onto when they died) and extreme "survivability" - to take one down permanently, you have to burn it.
Bran recognizes them in the book:
The wights, Bran realized. Someone set the wights on fire
Sources: A Dance With Dragons chapter 13 ; Book chapter summary; Wiki, season 4 appearances
These are White Walkers ("Others"):
They use ice weapons and magic, they are intelligent, and the only way to kill them is with Valyrian steel or Dragonglass.
Not even dragonfire can kill them, or at least the Night King, as shown in season 8 episode 3.