Know what to do when the MRT.app tool on your Mac uses high CPU usage.
What is MRT.app?
The Malware Removal Tool (MRT.app) is an application that lives in the CoreServices folder located in /System/Library, rather than the Applications or Utilities folders where user level programs are typically located. Despite taking the form of an application bundle, MRT is not supposed to be launched by users.
MRT.app makes Mac performance slow
Issues with Third-party Antivirus Apps
Apple will update MRT.app from time to time, with the latest updates. The content includes signatures of new malware.
Its updates affects other antivirus updates so some third-party antivirus software, which also contains the signature, mistakenly recognize MRT.app as malware. You will see the popup warning that MRT.app is detected as malicious.
Most Antivirus solution is to add it to the Exception List. However, there is a possibility for some malware to tamper with MRT.app. Adding this software to the Exception List will affect user’s Mac security.
Avoid False Positives with Antivirus One
Most antivirus software adopts a Localized Virus Pattern library. Antivirus One uses Cloud Virus Pattern to avoid false positives and ensure security.
Antivirus One will remove these malware to avoid MRT.app occupying a large amount of system memory.