Infosec Institute CTF Level 11

Bounty: $110 Description:

What another sound again??? No it must not be a sound? But wait whaT?

Write-up

Let’s look for any embeded strings to the image. Lucky enough, using “strings” again, we find the flag.

$ strings php-logo-virus.jpg | grep flag
infosec_flagis_aHR0cDovL3d3dy5yb2xsZXJza2kuY28udWsvaW1hZ2VzYi9wb3dlcnNsaWRlX2xvZ29fbGFyZ2UuZ2lm

However, the last part of the flag looks encoded. It looks like it’s base64 again, so let’s decode it.

$ echo -n 'aHR0cDovL3d3dy5yb2xsZXJza2kuY28udWsvaW1hZ2VzYi9wb3dlcnNsaWRlX2xvZ29fbGFyZ2UuZ2lm' | base64 -d
http://www.rollerski.co.uk/imagesb/powerslide_logo_large.gif

Downloading the gif from the extracted link, and opening it, it display’s “powerslide”. So the flag becomes:
infosec_flagis_powerslide

Links

• http://ctf.infosecinstitute.com/leveleleven.php