An accounting employee recently used software that was not approved by the company.

Shadow IT refers to employees using software or services without official approval, often introducing security risks due to lack of control, monitoring, or compliance. This can lead to vulnerabilities, data leakage, or policy violations.

Unskilled attacker (A) and hacktivist (B) are threat actor types; supply chain (D) refers to risks from external partners or vendors, not internal unauthorized software usage.

Shadow IT is highlighted in Security Program Management and Threats domains for its risk implications【6:Chapter 16†CompTIA Security+ Study Guide】.