A malicious file was executed automatically when a flash drive was plugged in.

AutoPlay is a feature that automatically runs programs or files when a removable media device, such as a flash drive, is plugged in. This can be exploited by malware authors who place malicious files on flash drives that execute automatically when inserted into a computer. Turning off AutoPlay can prevent this type of incident by requiring the user to manually open or run files from removable media devices. Disabling UAC (user account control), restricting local administrators and enabling UPnP (universal plug and play) are not effective ways to prevent this type of incident. Verified References: https://www.comptia.org/blog/autoplay-security-risk https://www.comptia.org/certifications/a