I have been trying to manually parse the PNG file that Q posted on >>141703 last night. An anon urged me to proceed with this analysis. See pics related. My comments are in pic related.

Basically I found some data within the file that does not seem to parse correctly. I am not sure how a standard PNG renderer handles data that is apparently malformed. There is a 12 byte field that does not appear to match anything in the Version 1.2 PNG spec.

A caveat: I have never tried to analyze a PNG file before so it is entirely possible that my analysis is off-base.

I did not study the entire file, just the beginning portion up to the first IDAT chunk. There may be more stuff in here when analyzed further…

Anons' feedback requested.