How to create a base64 data image url with a payload?

How to create a base64 data image url with a payload? - Printable Version

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+---- Thread: How to create a base64 data image url with a payload? (/showthread.php?tid=6128556)

How to create a base64 data image url with a payload? - AlphaRays - Dec 20, 2020

Hey guy,

Code 
data:image/jpeg;base64,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

If you decode above base64 image url, you will find that it has payload along with the image itself. My question is, how to make one like this. When i try to encode it back with some changes in the php payload, the image is simply being corrupted. I am sure this is not how it can be done. If somebody know some python script, or some write ups about it?

RE: How to create a base64 data image url with a payload? - jinpingxi - Dec 20, 2020

(Dec 20, 2020 11:26 AM)AlphaRays Wrote: Hey guy,

Code
data:image/jpeg;base64,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

If you decode above base64 image url, you will find that it has payload along with the image itself. My question is, how to make one like this. When i try to encode it back with some changes in the php payload, the image is simply being corrupted. I am sure this is not how it can be done. If somebody know some python script, or some write ups about it?

Have you tried getting a image, appending your php code then saving it as a normal image then encoding it through 'base64' default linux command?
I don't think actually base64 encoding it will work (If that's not what you're doing, I apologise)

* edit It's possible the code you see is EXIF data?
https://www.trustwave.com/en-us/resources/blogs/spiderlabs-blog/hiding-webshell-backdoor-code-in-image-files/