How do I avoid rice cookers emitting strange goo on my counter?
Some rice cookers have a vent on the side, and there's a little cup with it that clips in there to catch the starchy moisture that might escape during cooking.

If your rice cooker came with a small plastic cup (I say 'cup' as it's a container, but it's usually pretty flat so it doesn't stick out very far) that you couldn't figure out what it was for, this is likely your problem.  It usually attaches near the hinge.

Not all rice cookers have them, though.  My 10 cup does, but the little 2 cup that I got at a thrift store doesn't.  (it vents from the top, and the lid lifts off completely)