Agree..it does look like a schefflera. I would check the soil as suggested.
Oftentimes, tropicals grown indoors do slow down during winter time. So the plant drops the leaves it cannot sustain and will just keep what it will be able to handle. And I think if you can reposition the plant a bit further away from the window. The window might be getting too cold for it. But leaf drop means a lot of things, so check the condition of the roots and soil. Adjust further watering if it is still damp. If it looks damp, don't water. A skewer will also help you see if it is staying damp below soil line.
