Cops on Saturday arrested a woman suspected of randomly attacking a subway rider with a “sharp object” that may have been a hypodermic needle, police said.

Nicole Brown, 47, of the Bronx was busted in the alleged attack on a southbound No. 4 train at the 59th Street and Lexington Avenue station.

Brown is suspected of assaulting the female straphanger, 26, at about 11:30 a.m. Saturday, said police.

She is charged with assault and the manufacturing of a dangerous weapon. Police did not recover the weapon Brown allegedly used.

Brown’s victim was taken to New York Presbyterian Hospital/Weill Cornell Medical Center. She was listed in stable condition on Saturday afternoon.