It appears the leaker of the Kylo Ren full body image is being sought after by Lucasfilm according to Courthouse News:
SAN FRANCISCO (CN) – Lucasfilm is searching for whoever leaked a photo of the new “Star Wars” movie on an image-sharing network.
The film company filed a subpoena request in federal court today against ImageShack, under the Digital Millennium Copyright Act.
Lucasfilm seeks information that will identify user “Darth_Simi,” who allegedly posted at least one unauthorized image to the ImageShack site on Oct. 29, 2014.
I believe this is linked to the photo of Kylo Ren that leaked just before November.