Plain Sight Writeup - BCACTF 6.0

Foren/Plain Sight - Lam To

Can you help find my flag? I tried asking around but all I found was this poem.

Initial Thoughts

We are given hiding_in_plain_sight.pdf, which contains a lovely poem: Hiding in Plain Sight by Denise Riley

I try to find you, yet you are not here.
I’ve studied absence, fought to fill it in –
courage comes easier with a grasp of why.
A secret’s camouflaged when unconcealed.
I chose to not see/saw the thing too near?
Absence turns thicker, muscled by its strain.
A moon in daylight, whitest blue on blue,
surprises briefly, to appear surreal
until it slips to rights. I couldn’t spot
the obvious – obviam, in the way; plain
sight goes blind through chasing clarity.
I looked for you, so couldn’t see you gone.
I sensed your not-there in its burning life.
I listened out to feel its silence beat.
It does not speak with any human mouth.

My first thought was, like the Dessert Time challenge, to check for hidden text. Unfortunately, I found none.

Methodology

I then decided to check for hidden images in the PDF using I Love PDF.

This yielded the file img4.jpg, which contains our flag.

Solution

The flag is bcactf{Now_y0U_s3e_mE}. This challenge was pretty easy for me thanks to one of the forensics questions in DPRK - if you know, you know.