From Wikipedia,
A covert operation (also as CoveOps or covert ops) is a military, intelligence or law enforcement operation that is carried clandestinely and, often, outside of official channels. Covert operations aim to fulfill their mission objectives without any parties knowing who sponsored or carried out the operation.

Under United States law, the Central Intelligence Agency (CIA) is the sole agency legally allowed to carry out Covert Action. The CIA's authority to conduct Covert Action comes from the National Security Act of 1947.President Truman issued Executive Order 12333 titled in 1984. This order defined covert action as "special activities", both political and military, that the US Government could legally deny. The CIA was also designated as the sole authority under the 1991 Intelligence Authorization Act and in Title 50 of the United States Code Section 413(e). The CIA must have a "Presidential Finding" issued by the President of the United States in order to conduct these activities under the Hughes-Ryan amendment to the 1991 Intelligence Authorization Act These findings are then monitored by the oversight committees in both the US Senate and the House of Representatives.As a result of this framework, the CIA has the most oversight of any other government agency. The Special Activities Division (SAD) is a division of the CIA's National Clandestine Service, responsible for Covert Action and "Special Activities". These special activities include covert political influence and paramilitary operations. The division is overseen by the United States Secretary of State