A(n) _____ is a network attack in which an intruder gains access to a network and stays undetected with the intention of stealing data.

a. advanced persistent threat
b. vishing scam
c. identity threat
d. data breach

a. advanced persistent threat
An advanced persistent threat (APT) is a network attack in which an intruder gains access to a network and stays there—undetected—with the intention of stealing data over a long period of time. Attackers in an APT must continuously rewrite code and employ sophisticated evasion techniques to avoid discovery. APT attacks target organizations with high-value information, such as banks and financial institutions, government agencies, and insurance companies.