A software weapon is a type of weapon that damages a target by disrupting computer activity. Pieces of programming that damage a computer's orderly operations have been metaphorically linked to worms or viruses, because they reprogram or simply eat through data patterns. Other software weapons use energy or communications transmissions to cause incorrect signals to travel through computer circuitry, or simply blocking or drowning out the normal operation of circuits.
This type of weapon has been used by many races. For instance, some Borg diamonds were fitted with a computer override weapon which allowed the Collective to temporarily (before the target vessel's crew could repair the damage) control any enemy vessel. (TNG video games: Armada, Armada II)