The NSA has a term for the planting of malware inside computer networks Computer Network Exploitation The malware is designed to not draw attention to itself, waiting for months to steal information from compromised systems and feed it back to its spymasters. The malware can be controlled remotely and be turned on and off at will. The implants act as digital sleeper cells that can be activated with a single push of a button. All organisations need to ask themselves whether they could be a potential victim of state-sponsored espionage.”]
Source: https://grahamcluley.com/nsa-infected-50000-networks-malware/