From Destinypedia, the Destiny wiki
SIVA Nodes are objects in Destiny Rise of Iron that are utilized by the Devil Splicers to override and control old security systems and protocols in Cosmodrome Silos and facilities. They also act as area deniers, for if a Guardian steps in one's sphere of influence they get debuffed with "SIVA Swarm". Some Splicer bosses are capable of summoning these when faced in battle. These nodes can be destroyed by Guardian attacks.
List of appearances