The PSNI say the attack happened in the Killyglen Link/Lindara area of Larne during the early hours of Christmas morning, December 25, 2018.
Detective Constable Curry said: “The incident was reported at around 1am on Christmas morning and is believed to have occurred sometime between midnight and 12.45am.
“I am appealing to anyone who has information that could assist with the investigation, or who saw any suspicious activity in the area that morning, to get in touch.
“I am particularly keen to hear from the driver of a vehicle who gave the female a lift from the Old Glenarm Road area of Larne a short time before the incident, in case they may have any information that can help our enquiries.
“Please get in touch on the non-emergency number 101, quoting reference number 72 of 25/12/18.
“Information can also be provided to the independent charity Crimestoppers on 0800 555 111 which is 100% anonymous and gives people the power to speak up and stop crime.”