Shield around exhaust pipe removed

2016 Prius v from Canada.

I parked overnight in the street in Boston last weekend. The next day, I was hearing a rattling/grinding sound at low speed, 20-30 kms per hour, and when accelerating from a stop.

I had front and back brakes done a few days earlier so thought that might be it.

But when I got under the car, I saw what seemed to be the source of the noise: a sliver light metal “shield” that was resting on top of the exhaust pipe, about midway down the length of the vehicle.

I could move the piece around and it didn’t seem to be anchored to any other part of the car. At one end of the shield, closer to the engine, there are two holes that look to be bolt holes but no bolts.

By guess is that someone was trying to steal the catalytic converter and removed the shield, but maybe gave up or was interrupted.

I think the shield should be on the underside of the exhaust pipe but I’m not sure. And don’t know if this is something I could fix myself easily.

Any ideas?