The girl got away after fighting back and biting the suspect's hand.
Investigators say the man grabbed the girl and tried to drag her into a wooded area Wednesday in the 9600-block of Golf Road in Maine Township near Des Plaines.
Some white headphones the man was wearing have been recovered, but he remains on the loose.
The 12-year-old girl carefully described the attacker to authorities, providing valuable details for this sketch.
"He grabbed her, put his hand over her mouth and started to drag her into a wooded area," said Cook County Sheriff Tom Dart. "She fought hard, and frankly, did something that all of us in law enforcement would want her to do."
She bit him and ran to her apartment nearby.
It happened Wednesday afternoon. The girl was riding her bike and paused at a lake in Maine Township when the man attacked.
"A lot of sex predators in this area," said resident Dawn Dickens. "So it might have been one of them that tried to abduct that little girl."
Investigators are focusing on that exact angle: 25 sexual predators live in the area.
Cook County authorities are canvassing nearby businesses, hanging up fliers, and pulling surveillance video.
"I have never heard of anything like this before," said resident Mahalia Cothran. "It kind of scared me."
"It does worry me," said long-time resident Bill Pampel. "The area has changed so much."
Anyone with information should call the Cook County Sheriff.