The baby was left at the store at the Philadelphia Mills Mall around 11 p.m. Thursday.
Police say store security approached a woman and two men about a retail theft at the store but they fled the scene.
When guards returned to the store, they discovered the infant who had been left behind.
She was rushed to Jefferson-Torresdale Hospital and is in stable condition.
Police are now searching for the trio who abandoned her.
Anyone with information about this incident is asked to call police at 215-685-3260.