Steamy cellphone shots of the curvy Lost In Translation star began circulating in cyberspace on Wednesday (14Sep11).
One image appears to show the star lying topless in bed, while in another, the blonde beauty can be seen taking a photograph of her bare backside in a bathroom mirror.
Johansson is the latest star to fall victim to a naked photo scandal - Vanessa Hudgens, Rihanna and Ashley Greene have all been embarrassed by candid snaps that have surfaced online.
The actress' publicist has failed to respond to WENN's repeated requests for a comment, but Internet reports suggest Johansson has been targeted by a hacker.
Sources tell TMZ.com Johansson plans to get the FBI involved because she believes the scandalous leak is a criminal act.