The woman was walking home from a pub past Gloria Mortimer Oval about 1.25am on Friday when five males approached and then attacked her, police said.

She later made it home and told her family before being taken to the town's hospital.

The alleged assault was reported about 3am.

Investigators say the victim recognised four of the five alleged attackers.

"She believes that four of them are locals that she's seen around town," Richmond Local Area Command Inspector Brad Walpole said.

Inspector Walpole said the assault was very rare for the area.

"It's horrendous," he said.

Detectives believe the alleged assault could be connected to a car stolen around Tabulam, west of Lismore, before the attack, Inspector Walpole said.

A crime scene was established at the oval and examined by forensic officers.

But police are appealing for public assistance to find the alleged attackers, whom they described as being of Aboriginal or Torres Strait Islander appearance.