Rating:
### Solution:
I really over thought this one. Running the file through pngcheck right off will show a bad section with the text "EASY". I pulled it up in a hex editor and found 4 instances of "EASY". Pulling up a second png for comparison it was pretty easy to tell that section should be "IDAT". The others were burried farther in the file and I didn't have any guesses so I ran the file back through pngcheck and it spit out some other sections that were off, but nothing helpful.
Time to do some learnin'. Wikipedia helped a little, but the libpng site (http://www.libpng.org/pub/png/book/chapter08.html and http://www.libpng.org/pub/png/spec/1.2/PNG-Chunks.html) helped a lot. At this point I figured I just needed to figure out what the other png chunks should be called and read up some more to see if I could find anything useful before I just started replacing stuff at random. While doing that it seemed a little odd that the chunk lengths I kept running into were an even 0x200 (8k). Then I read png's can have multiple IDAT's that the app creating them can string together in any size it wanted. Oh...these are all IDAT. Yeah...that would have been easy if I tried that on a whim right off. Search replace EASY with IDAT and poof, working image.
### Flag:
shkCTF{7uffy_1s_pr0ud_0f_y0u_0a2a9795f0bdf8d17e4}
