The incident occurred between 2am and 3am on Thursday (9 August 2018) when an unknown man gained entry into a home in the Haywra Court area, off Haywra Street.
He assaulted a woman aged in her early 60s inside the home, causing bruising to her face.
He made off with wallets and mobile phones.
The suspect is described as white, aged 20 to 30, about 5ft 6in tall and he was wearing a dark, possibly green, hooded top.
Detective Constable Paul Smith, the investigating officer, said:
This is a particularly heinous crime which subjected the victim to a terrifying experience. She is being supported by the police and measures have been put in place to enhance security at the property.
Police patrols have also been stepped up in the area to provide reassurance to the local community while enquiries continue into what appears to be an isolated but very disturbing incident.
I am appealing for people to come forward with any information about suspicious activity in the area of Haywra Court at the time of the incident or in recent days.
In particular, we need to know about possible sightings of a man in a dark hooded top who matches the description given.
Even the smallest piece of detail could be vitally important to the investigation.
If you can help, please call North Yorkshire Police on 101, select option 2, and ask for Paul Smith. Or email Paul.Smith@northyorkshire.pnn.police.uk
Alternatively, contact Crimestoppers anonymously on 0800 555111.
Please quote reference number 12180147093 when providing details about this incident.