What's a stealthy and continuous computer hacking process often targeted at a specific entity?

What's a stealthy and continuous computer hacking process often targeted at a specific entity?

• Shadow ninja attack
• Advanced persistent threat
• Advanced malware attack
• Silent and deadly attack 

 

EXPLANATION

An advanced persistent threat (APT) uses multiple phases to break into a network, avoid detection, and harvest valuable information over the long term. The intention of an APT attack is to steal data rather than to cause damage to the network or organization. APTs require a high degree of covertness over an extended period of time.