Onions

Ogres are like files -- they have layers!

Provided is the following image:

Recon

The image file contains a 7z archive.

$ binwalk -e shrek.jpg 

DECIMAL       HEXADECIMAL     DESCRIPTION
--------------------------------------------------------------------------------
0             0x0             JPEG image data, JFIF standard 1.01
275566        0x4346E         7-zip archive data, version 0.4

$ dd if=shrek.jpg skip=275566 bs=1 of=shrek.7z
538+0 records in
538+0 records out
538 bytes transferred in 0.004100 secs (131217 bytes/sec)

The 7-zip archive contains several more archives and finally a flag file.

Flag

TUCTF{F1L3S4R3L1K30N10NSTH3YH4V3L4Y3RS}