Ghost Hunter

Challenge:

We intercepted this image from a user on Ghost Town. Some kind of tool was used to hide information in this image.

Solution:

I spent time analyzing the image with binwalk, strings, StegSolve, pngcheck, etc. which didn't produce any results. I found success after using zsteg and searching for the string "flag":

$ zsteg -a ghost_01.png | grep flag

b2,rgb,lsb,yx       .. zlib: data="flag{8862a805a3140996343da91bdcbda79e}", offset=61, size=38