The challenge was delivered as a zip file (InsomniDroid.zip). The first challenge was perhaps to download it (with its 602.5 MiB). The zip file contains a single file: mmcblk0.dd. A file command gives some information
more here.....http://blog.scrt.ch/2015/03/27/insomnihack-finals-insomnidroid-level-1-writeup/
more here.....http://blog.scrt.ch/2015/03/27/insomnihack-finals-insomnidroid-level-1-writeup/