The robbery happened at 4:05 a.m. on November 11th in the 700 block of South 9th Street.
Investigators released surveillance video of the suspect on Wednesday morning.
Police say the suspect approached the victim from behind and struck her in the face with an unknown object, causing a large cut.
That wound needed 100 stitches to be closed, police said.
The suspect then grabbed the woman's purse and fled north on 9th Street, then east on Fitzwater Street.
The purse was later found in a small alley at 800 Kenilworth Street.
The victim, 23-year-old Ashley Hackett, spoke at a news conference on Wednesday morning and asked that anyone with information come forward.
She said the attack happened not far from her home. "I live in a safe neighborhood. I want to make sure my neighborhood is safe, I want to feel safe walking down the street," she said.
Ashley went on to say that the man didn't say anything and she had no idea he was there until he was right over her shoulder.
Ashley said she screamed for help during the attack and managed to run to her front door. She said her neighbors came over and sat with her, called police and medics, and tried to help control the bleeding.
"I needed safety, and they were my safety net. They were incredible," she said.
The suspect is described as a white male with a thin build wearing a white hooded sweatshirt with an emblem on the left side of the hood, black pants and dark-colored shoes.
The Philadelphia Fraternal Order of Police is offering a $7,500 reward for information leading to an arrest in this case. Meanwhile, the City of Philadelphia is offering a reward of $5,000 for the arrest and conviction of the suspect.
Anyone with information is asked to contact Philadelphia Police at 215-686-TIPS (8477), text a tip to PPD TIP (773847) or through phillypolice.com.