English [MITRE STEM 2015] [Crypto 300 – Daba Dee Daba Die] Write Up

Description

Yo listen up here’s a story
About a little guy that lives in a blue world
And all day and all night and everything he sees
Is just blue like him inside and outside
Blue his house with a blue little window
And a blue corvette
And everything is blue for him and himself
And everybody around
‘Cause he ain’t got nobody to listen to.

Resolution

As stated in the description, we had to deal with the blue !
We opened the image, and .. well… it’s blue 😀
Nothing here, in the layers, but the end of the image is strange…

A well known method to hide data in images is to play with the Least Significant Bit, or with the Most Significant Bit.
It’s visible as it renders some weird pixels, like here 🙂

We used StegSolve to check if our doubts are based.
After playing with the settings (Analyze/Data Extract) we found the correct one :

blue_resolv

Flag was : MCA-2fa2b3d4

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