You can actually change your MAC address, so that may have happened here. Not sure how to go about it in Windows, but in Linux you simply open a terminal and enter:
sudo ip link set dev [interface] address XX:XX:XX:XX:XX:XX
Wouldn't be able to speak on why these ones might have been changed, but I will say there are legitimate reasons to change a MAC address. You don't see it done often, but it doesn't set alarms off in my mind on its own. We'd need more evidence before I'd call it nefarious.
You can actually change your MAC address, so that may have happened here. Not sure how to go about it in Windows, but in Linux you simply open a terminal and enter:
Wouldn't be able to speak on why these ones might have been changed, but I will say there are legitimate reasons to change a MAC address. You don't see it done often, but it doesn't set alarms off in my mind on its own. We'd need more evidence before I'd call it nefarious.