Oraios

From FEInfobase

Oraios, more properly designated as Oraios IV, is a Minshara-class planet located somewhere near Klingon space. It is largely uninhabited, although it has the wreckage of the Ambassador-class USS Ark Royal, and an alien facility now inhabited by Starfleet survivors, Oraios Base.

The star system it is a part of, also dubbed the "Oraios System", has an abnormal Oort cloud, which distorts subspace, interfering with warp drive operation, as well as scrambling any subspace communications, including the frequencies used by the Borg to connect drones to the Collective.