I cannot speak for the Catholic Church as a whole, but having been enrolled in a Roman Catholic elementary school during the day when I was a boy as there were no Jewish schools where I lived (I had Hebrew school in the evening), my catechist, Fr. Eugene Caserly of Little Flower Catholic Church did tell a couple of Jehovah's Witnesses who had this question the following.
This is from a long time ago (I'm old) when the Society still had those awful green-colored Bibles and magazines were filled with mostly hand-drawn, two-colored illustrations. (I was a kid back then.)
Fr. Eugene said the two "Jehovahs" knocked on his door not realizing it was a rectory. They were quite surprised when a collared priest came to the door and so they just stumbled through their presentation.
They tried to engage him in a conversation and offer him "some books or pamphlet" but the shock of meeting a priest and being ill-prepared just never seemed to wear off.
So upon coming to the end of what seemed like a fiasco, one of them actually asked this question: "Do you mind telling me, sir, what do Catholics really think of us Jehovah's Witnesses?"
Fr. Eugene grinned at the two men as he grabbed hold of his front door, and replied: "We don't."
And with that, he slammed it on them.
I don't think there's anything official either, so I wouldn't be surprised if Fr. Eugene's view was pretty spot on not just for Catholics but most folks.
People don't even know JWs are around.