perfect tool, glad I know about that one now. :-)
Unfortunately, according to that tool I do not have any VM with MAC 00:50:56:73:b6:97 or 00:50:56:71:5d:a9.
The MAC addresses are not in the dynamic range 00:50:56:b7:... nor in the manual range 00:50:56:00:...
The "flexible" adapters have a 00:0c:29:.... address, so that's not it either.
So what could it be?