The woman was at Crystal Peaks shopping centre when two cards were stolen but only noticed they were missing from her purse after getting back to her home that afternoon.
When she checked her online banking, she found that two cash withdrawals for £300 each had been made at a Halifax branch within Crystal Peaks.
Detectives investigating the crime, which happened on Thursday, September 30, between 2.15pm and 3.45pm, have released this CCTV image of two men they would like to speak to in connection with the theft.
Police believe the men who are pictured may be able to assist with their enquiries.
Anyone with any information is asked to call South Yorkshire Police on 101, quoting the crime reference number 14/151602/21, or to call Crimestoppers, free and anonymously, on 0800 555 111.