B737-800 Captain reported encountering wake turbulence descending into BWI in trail of a B767.

Narrative

While descending via the ANTHM 3 Arrival into BWI; passing BUBBI at 18;000' and 280 KIAS; the aircraft hit moderate wake turbulence; causing the autopilot to disconnect. Conditions were smooth and expected smooth on the arrival. Passenger seat belt sign was on and Flight Attendants were out of their seats and performing normal duties. The First Officer asked Washington Center what kind of aircraft we were behind on the arrival; and approach informed us it was Aircraft X. We asked to slow down to 250 and felt a little more wake and then asked for vectors off course on the arrival. The First Officer then called the Flight Attendants who were okay but were jolted by the wake turbulence. We increased spacing with Aircraft X and continued to a normal visual approach and landing. The Flight Attendants did not require medical attention. The D position was done with her trip and went home. The A; B; and C were going to continue flying another flight. Two of the Flight Attendants; I think the B and C; mentioned their backs hurt but that they could keep flying and would be okay. No passengers were injured.