id-me is a
challenge I wrote to teach people how to determine file types without extensions.
My intent was to use the
file command, but other solutions are absolutely
id-me to be a fairly straight forward “identify this file”
challenge. The user is given four files, and they are tasked with reading part
of the flag from each of them.
I’d personally use the
file command on Linux:
$ file * file1: ASCII text file2: JPEG image data [...] file3: PDF document, version 1.4 file4: Zip archive data, at least v2.0 to extract, compression method=deflate
But lots of other ways exist, including simply opening them in the Chrome browser.