JPG Injector

Inject any kind of data into a JPG image without affecting it.

Commands:

inject [input.jpg] [payload.*] [output.jpg]

Injects the specified payload into the specified JPG

extract [injected.jpg] [extracted_payload.*]

Extracts injected payload from the specified JPG into a separate file

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Example

We have a JPG image

cat.jpg

and some kind of data (can be a file of any type)

supersecret

my credit card number
6969696969696969696969

Using the inject command, you can inject the cat.jpg image with the contents of supersecret without affecting the cat.jpg image at all.

jj inject cat.jpg supersecret cat_injected_with_supersecret.jpg

Output:

cat_injected_with_supersecret.jpg

As you can see, it has not changed a bit.

Now, you can extract what you just injected using the extract command.

jj extract cat_injected_with_supersecret.jpg payload.txt

Output:

payload

my credit card number
6969696969696969696969