runtimebroker.exe is a application which is probably legit. So, if runtimebroker.exe is on your computer, it is probably ok, and will NOT be a cause for concern. Even if your PC is virus-free, it is still recommended to use a well-known antivirus with a good track record, in order to yourself your system against viruses and malware.
Usually, this application is found in C:\Windows\System32\RuntimeBroker.exe.
The MD5 fingerprint for this executable is bd4401441a21bf1abce6404f4231db4d.
This program is NOT a Windows service. This is good.
runtimebroker.exe appears to have something to do with Windows SFC (System File Checker) or Windows File Protection.
This is a 64-bit executable. It uses the full capacity of nowadays' CPUs.
This program does NOT have visible elements of user interface. This is most likely a bad sign.
runtimebroker.exe has a digital signature. Nowadays the large majority of serious software applications are digitally signed.
The digital signature attached to runtimebroker.exe is valid. This is most likely a clean, ok program.
Digital certificate name: Microsoft Windows
Certificate's issuer name: Microsoft Windows Production PCA 2011
This program does NOT have an uninstall command set up in registry.