Rundll32.exe executes DLLs and places their libraries into memory. If it is found in WinSxS, System32, or SysWOW64 folders it is the legit process; else malware.

Is MOM.exe a virus The legit MOM.exe process is located in the C:\Program Files (x86)\ATI Technologies\ folder. If it is located elsewhere, it could be malware as a virus can have any name.