It says increase damage by 6% with attacks (it says in the spanish language), but it doesn't increase any damage.
it was supposed to be fixed in this patch: 1.0.8.0 "Fixed an issue in the computation of the Static Transferral passive node."

Update: This passive increases only my skill damage, but not my basic attack damage. But as I say before, the text says it:
"Cada vez que usas tu Ataque Básico, recibes un Punto de "Sobrecarga" que aumenta tu Daño..." "6% de Daño por Punto de Sobrecarga"
Translated says it:
"Each time you use your Basic Attack, you receive an "Overload" Point that increases your Damage ..."
If it is not a bug, the text should say:
"Each time you use your Basic Attack, you receive an "Overload" Point that increases your SKILL Damage ..."

Greetings!