Runtime Broker is using too much memory - Microsoft Support
Runtime Broker is a Windows process in Task Manager that helps manage permissions on your PC for apps from Microsoft Store. It should only use a few megabytes of memory, but in some cases, a faulty app might cause Runtime Broker to use up to a gigabyte of RAM or more.
How to remove the PC Repair virus - Microsoft Support
Resolution. This issue can be resolved and the PC Repair virus removed by running the Microsoft Safety Scanner. To do this, follow the steps below: Go to http://www.microsoft.com/security/scanner/en-us/default.aspx and click the Download Now button.