Who is defined as a "malicious insider" in data security context?

In the context of data security, a "malicious insider" refers to an individual within an organization, such as an employee, who uses their authorized access to the organization's systems and data with the intent to cause harm. This can manifest in various forms, such as stealing sensitive information, sabotaging data, or facilitating external attacks by providing internal access. The key element defining a malicious insider is the dual role they play as both a trusted member of the organization and a perpetrator of malicious actions, using their knowledge of internal processes and systems to exploit vulnerabilities.

The other choices illustrate different scenarios but do not align with the definition of a malicious insider. For instance, following company policies meticulously does not indicate any malicious intent. A contractor who learns from external hacking may not be operating within the organization or having insider knowledge, and a vendor managing software securely would also not fit the description, as their role typically revolves around external support rather than internal sabotage or data misuse. Hence, the hallmark of a malicious insider lies specifically in their harmful use of legitimate access to organizational data.