Kate Upton — FBI Probes to See If Hacker Hooked Her and 3 Others by Phishing

EXCLUSIVE

The leaked photos of Kate Upton and her boyfriend didn’t get out because of an iCloud security breach … but instead she may have been the victim of one of the oldest tricks in the online scamming game.

Law enforcement sources tell TMZ … FBI investigators are looking into whether Kate and at least 3 other celebs — Mary Elizabeth Winstead, Jennifer Lawrence, and Lea…