It doesn't contradict anything, it just lowers the probability of being right a hair (For the extreme few APTs who would bother with such trivialities), hence t

It doesn't contradict anything, it just lowers the probability of being right a hair (For the extreme few APTs who would bother with such trivialities), hence the "attribution is bullshit" -- you can't ever know. However, that does NOT contradict the simple fact that various APT groups do absolutely use the same tried and true TTPs get get in, gain foothold, and persist. They evolve them over time, but you'd be foolish to think they entirely wing it each time, using a chaotic set of techniques. They establish patterns, and you can absolutely build a signature off of that.