Several wounds were spotted on Zakia Sultana Rupa's head and body, Tangail Sadar Hospital Resident Physician Saiful Islam told bdnews24.com.
The hospital submitted the victim's autopsy report to the civil surgeon on Tuesday night, he said.
"She died from multiple blows to the head. She was raped before the fatal attack."
A student of Dhaka's Ideal Law College, Rupa worked in Mymensingh for the marketing wing of a company. Her family is from Sirajganj's Tarash.
Rupa was attacked by five staff members of the bus including its driver and superviser after her colleague got off in Tangail.
Her body was found dumped on the Tangail-Mymensingh Highway at Modhupur's Panchish Mile area around 11pm.
Police after arresting the men said they had confessed to raping the young woman while the bus was travelling from Kalihati to Modhupur.