Advanced persistent threat

Definition
An advanced persistent threat is an adversary with sophisticated levels of expertise and significant resources, allowing it through the use of multiple different attack vectors (e.g., cyber, physical, and deception), to generate opportunities to achieve its objectives, which are typically to establish and extend footholds within the information technology infrastructure of organizations for purposes of continually exfiltrating information and/or undermining or impeding critical aspects of a mission, program, or organization, or to place itself in a position to do so in the future.