Description

We found this very mysterious image, it doesn’t look complete and there seems to be something hidden on it… does this mean anything to you?

This flag is not in the standard flag format. The flag contains digits and no special characters, convert the message to lowercase and then add IceCTF{message} to it.

Resolution

Using Google Images, we have found the image is a part of this book:

Looking in EXIF data we got:

58-7-9
210-13-2
67-3-16
85-17-15
305-18-4
83-12-18
75-8-15
47-4-2
83-20-11
208-6-6
85-11-6
75-7-3
106-9-14

The code used here is a variant of the Book Cipher:
58-7-9 = 58th page, 7th line, 9th word.

With multiples tries we got:

58-7-9        not  
210-13-2      0s
67-3-16       one
85-17-15      becomes
305-18-4      zero
83-12-18      routed
75-8-15       3
47-4-2        authenticity
83-20-11      David
208-6-6       be
85-11-6       of
75-7-3        0
106-9-14      x

Flag was IceCTF{n0obzr3adbo0x}