Root compromise

Definition
A root compromise

"is similar to an account compromise, except that the account that has been compromised has special privileges on the system."

Overview
The term root is derived from an account on UNIX systems that typically has unlimited, or "superuser", privileges. Intruders who succeed in a root compromise can do just about anything on the victim's system, including run their own programs, change how the system works, and hide traces of their intrusion."