A young male wearing dark clothing with a hood pulled up approached the woman while she was in her car in the grounds of Lidl supermarket on Halifax Road, Todmorden, and tried to grab her handbag by reaching in through the passenger door.
The victim kept hold of the bag and hit out at the male who fled up Halifax Road after a brief struggle.
Calderdale District CID would like to speak to anyone who saw the incident which took place between 7.05pm and 7.15pm last Tuesday.
The suspect is described as slim and about 5ft 8ins tall.
Detective Constable Lee Mason said: “I would ask anyone who may have seen this male or anyone who has had any information about the incident or the males identity to contact myself, DC Lee Mason, at Halifax CID on 101 or to contact the independent Crimestoppers charity anonymously on 0800 555111.”