A bright coloured fish

MP3 files can be ā€˜tagged’ with various pieces of data. I wanted to experiment with putting bad data in an MP3 file to do all sorts of nefarious things. I found a piece of software called Kid3 which can be used to write this data. I noticed a strange option for an image field

Kid3 screenshot featuring the bright coloured fish option

This is actually part of the spec.

The ID3 specification defines various ā€œAttached picturesā€ that can be added to an audio file.

Among options like $10 ā€˜Movie/video screen capture’, and $03 ā€˜Cover (front)’, there is also $11 ā€˜A bright coloured fish’.

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