Definition
An insider threat refers to a security risk originating from within an organization, posed by individuals who have authorized access to its systems and data. This threat can be malicious, such as an employee intentionally stealing sensitive information, or unintentional, like an employee accidentally exposing data through negligence. In practice, insider threats exploit legitimate access privileges to bypass perimeter defenses, making them particularly difficult to detect. Understanding and mitigating insider threats is crucial for maintaining data confidentiality, integrity, and availability, as well as protecting an organization's reputation. For example, a disgruntled former employee retaining access credentials and leaking proprietary code exemplifies a malicious insider threat. This differs from an external threat, which originates from outside the organization's network and typically attempts to breach defenses. Concepts related to insider threats are frequently covered in cybersecurity certifications like CompTIA Security+, CySA+, and CISSP.