Does a venom spur count as a weapon with the injection property, for the purposes of a biohacker's injection expert class feature?
EDIT: For that matter, is it an unarmed strike? A basic melee weapon? Does it benefit from Weapon Specialization?
As written, it does not have the injection property, and can't be used for biohacker class features.
It also appears to be one of those unique attacks that isn't any of those things, and doesn't get weapon spec either. I could be wrong about that.