The Malware Removal Tool (MRT.app) is an Apple 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.
Here are the common concerns regarding MRT.app below:
MRT.app uses high CPU and makes Mac performance slow
Compatibility with Third-party Antivirus Software
Apple will update the apple built-in software from time to time, with the latest update in July 2019. The updated content includes the signature of new malware.
The update of apple built-in sofware lags behind the update of other antivirus software so that some 3rd-party antivirus software, which also contains the signature, mistakenly recognize the software as malware. In this case, user will see the popup warining that MRT.app is detected as malicious.
The general practice for most of Antivirus software is to add it to the Exception List. However, there is a still some possibility for certain malicious software to tamper with MRT.app. Adding this software to the Exception List will affect user’s Mac security.
The root cause of the problem is that most antivirus software adopts localized virus pattern library. To avoid false positives and ensure security as well, Antivirus One adopts Cloud Virus Pattern.
Antivirus One will remove the malicious software in the first time, so as to avoid MRT.app occupying a large amount of system memory.