There are many answers here and the very same result could be achieved in many ways:

• Unicode/homomorph attack

using Unicode characters e.g. from Russian alphabet; this can be usually easily detected from a command line level:

• GUI attack

it is relatively easy to modify the content of any other window, including windows used by Explorer to display file names (window class is a standard ‘SysListView32′); some malware use GUI attacks to remove their processes’ names from a list of processes shown by Task Manager

• API hooking

trivial to return two exact file names for two different entries

• patching the file system entry directly

and probably a few more…