CPU utilization is the proportion of a processor’s available capacity being used by a process or by the system as a whole. On multicore systems, some monitoring tools add usage across cores, so a reading above 100% can indicate that multiple cores are busy. High utilization may be normal during demanding work, but sustained, unexplained load can make a device slow, hot, or noisy.
In cybersecurity, an unexpected CPU spike can be an early clue to investigate, including for resource-intensive malware such as cryptocurrency miners. Check which process is consuming resources, then verify its executable path, parent process, startup items, and network activity. CPU usage alone does not prove malicious activity: legitimate software can also use substantial processor time, and a process name does not establish how it was installed or whether it is authorized.