Hiding in Plain Sight — metactf

Description

There's something strange about this image but I can't put my finger on it, any ideas? The flag will be the name of the person or object you find, in the format DawgCTF{Chicken_Sandwich}.

File: https://metaproblems.com/9158c536955b3b93c3b1ec47841cc0ff/hello.webp

The file is a 1024x1024 lossy WebP showing a detailed classical sculpture: a muscular bearded male figure (Poseidon / Neptune style) covered in green moss, set against a fountain / water background. Note that even though the event is metactf, the flag format is DawgCTF{...} — the challenge was reused from DawgCTF (UMBC). Always follow the format in the task description, not the event name.

Analysis

1. File-level recon — nothing hidden

Standard stego checks all came back empty:

file hello.webp
# RIFF (little-endian) data, Web/P image, VP8 encoding, 1024x1024, lossy

exiftool hello.webp
# Only size/dimensions, no EXIF / XMP / ICC

strings hello.webp | grep -iE 'flag|ctf|dawg|key|secret'
# nothing

Manually parsing WebP chunks confirms a single VP8 chunk with no extra EXIF, XMP , ICCP, ANIM, or ANMF chunks, and no trailing data after the RIFF container:

with open('hello.webp', 'rb') as f:
    data = f.read()
assert data[:4] == b'RIFF' and data[8:12] == b'WEBP'
i = 12
while i < len(data):
    cid = data[i:i+4]
    csize = int.from_bytes(data[i+4:i+8], 'little')
    print(cid, csize, i)
    i += 8 + csize + (csize & 1)  # chunk + padding
# VP8  85836 12
# End at 85856 == filesize

So this is not file-level / LSB / metadata stego. The "strange" thing has to be visual.

2. Reading the hint literally

• Title: Hiding in Plain Sight
• Description: "There's something strange about this image but I can't put my finger on it"

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