It happened on Tuesday, November 10th at 10:00 a.m.
The 42-year-old woman was boarding the "M" train at the Broadway and Houston Street station when the suspect walked up behind her, sexually assaulted her, and then fled the station.
The suspect is described as a 35-year-old black man, with a heavy build, wearing metal frame glasses and a backpack.
Anyone with information in regards to this incident is asked to call the NYPD's Crime Stoppers Hotline at 800-577-TIPS.
The public can also submit their tips by logging onto the Crime Stoppers Website at WWW.NYPDCRIMESTOPPERS.COM or texting their tips to 274637(CRIMES) then enter TIP577.