I got an interesting rejection from a 4chan board when trying

>>347493
yes its called steganography, but i doubt that happened to you, i've got that error a couple of times as well with a couple of .gifs but it's probably something else.

https://www.youtube.com/watch?v=BQPkRlbVFEs
https://www.youtube.com/watch?v=hajOlvLhYJY

>>347493
just save it as png/gif or change its compression ratio

>>347493
Here's the address to the pic that caused this.

https://im9.eu/picture/hentai-girl-rejects-threesome

I downloaded it because of the joke in it and thought I could use it in a thread.

>>347493
You just concatenate it.

JPEG readers look for the JPEG header then read as many bytes as the JPEG header says to then close the file. MP3 readers, by contrast, scan the whole file and play anything that looks like an MP3 frame, so if you put an MP3 on the end of a JPEG, you get a file that plays as an MP3 when you call it a ".mp3", and displays as a picture when you call it a ".jpg".

You can also deconcatenate them because the JPEG header tells you how many bytes to remove.

Back in the day this was used to post files to 4chan, until the board software was changed to reject JPEGs with extra crap on the end.

I doubt the classification algorithm is particularly sophisticated because there's no reason a JPEG should ever have crap on the end and no real downside to just banning all JPEGs that do: if someone really wants to post it they can just trim the crap off.

>>347500
its comment section contains html code

>>347493
I don't think you can make a JPEG that's also a .EXE at the same time, because I think the PE header needs to be at the start and so does the JPEG header, but I don't want to speak authoritatively when I'm not qualified.

You can certainly stick a .EXE on the end that someone would be able to run after splitting the file.

File: Screenshot from 2017-07-16 00-49-56.png (1MB, 868x806px) Image search: [Google]

1MB, 868x806px

>>347497
>>347498

>>347502
>>347503
>>347505

Ok, thanks for the heads up. I took a screenshot of it for your convenience if you want to do a RIS. Not really hentai, it's just about that joke in it.

I'm running debian with gnome desktop so I don't think these are much of a threat to my rig.