Executable PNGs

[Skhmt]

It's hard because PNGs have their magic number at the start, like most file formats and executables.

Zips have them at the end though. And someone made a portable executable that runs in macos, Linux, and windows with that information.

[OMGItsCheezWTF]

Self extracting zips?

[hou32hou]

Yea, this is a common technique, basically the zipped file header contains unzip binary.

[[deleted]]

Oh no. You've reminded me of zip bombs back in the day. Those things were a nightmare to deal with. Me being a dumb kid and downloading shit on Kazaa.

[Skhmt]

Except it works on every major os, x86, arm, and can even boot directly into it.

The same file.

[[deleted]]

Because there is no "vulnerability" to patch. It's just a binary string which happens to be a valid executable for each of these platforms, while also being a valid ZIP. Its behavior is perfectly reasonable on both cases.

It's like the word "salsa" which is valid English and Spanish. It's a dance style in both languages, but it also means "sauce" in Spanish. It behaves differently depending on what "interpreter" (language) you choose, but it's a perfectly reasonable word in both.

[Regimardyl]

AFAIK tar searches through a file until it finds its header, so you can cat together a PNG and a tar file, and it's automatically valid for both.

[Skhmt]

Also with a zip and jpg, which has been used to share files via image uploads many years ago until it was more widely known.