Assimp exported file, 3D model format. Import to assimp, export to .obj. Open in blender, it's a QR code.

Setup a shader to lerp white->black based on height, then scan the QR code.

rgbCTF{3d-1337!}

The image has a QR code in the corner with a red and green channel. Extracting the channels and converting to BW gives us Green: xmasCTF{YoullShootYourEyeOutKid} Red:

rgbCTF{BESURETODRINKYOUROVALTINE}

The file is a raw hexdump. De-hexdump-ing this and checking the filetype in cyberchef shows it is an xz compressed file.

Using an online tool, https://extract.me/, you can extract a file from it.

This gives us the HTML for an SVG.

This SVG will form a QR code, but it's much easier to notice by replacing the #fffff6` colour with#000000 using` find and replace.

Scanning this QR code gives some base64 encoded data. Decompress this, and you get another xz file. Extracting this gives an ASCII art for a QR code - in inverted colours. Swap the colours and scan for the flag.

flag: rgbCTF{iCanHaz4N6DEVJOB}

We get two audio tracks.

One of them has a message about turntables in base64 in the spectogram, which seems kinda useless.

So to get the difference between the tracks, I inverted track one, then used audacity to mix and render the two to a new track (effectively subtracting track1 from track2) giving us the flag in a spectogram.

rgbCTF{s3v3r3_1nv3r71g0}

I had no clue, so thought of a ton of things, eventually coming back to some physics lessons with waves.

We can use a spectrum analyser to see "the magnitude of an input signal vs frequency within the full frequency range of the instrument". I used spek (spek.cc) to do that, and it loads in the flag.

Flag: rgbCTF{s331ng_s0undz}

Using the same method as 1 and 2 we use spectrogram stuffs to get chunks of text in each audio clip using briefing hints (and guessing) we sort these by decreasing time length to get a string: janOHS{ahse0n1yz_k4f73p}

We then guess vigenere and uh after some trial and error (and using the flag format as a guide) i got a partial key of "summon", so i just guessed the key was summoningsalt by the theme and also the briefing to get the flag.

flag: rgbCTF{summ0n1ng_s4l73d}