This is my first post on /g/, i spend most of my time on /k/

All files are binary files, how you interpret the bytes is completely up to you (or to a program). An interpretation is called a format. Hence you can have the same file that can be (interpreted) in different formats. In this case, there's a jpg-file (with some seeming random garbage at the bottom) but it's also a zip-file.

The technique is a form of steganography. Many moons ago anons would share stuff on imageboards like that, mostly books. It's completely unsecure however, anyone who knows to look for it can find (write a script to detect) it.

>>58696876
>encryption
Its not encryption

>>58696962
My bad, i wasn't sure as to what it was called exactly, so i used the first word i thought of to describe it.

>>58696954
Ah okay, thank you for the information

>>58696876
I'm more interested as to why manufacturing something so random is a felony, what the fuck is that?

>>58697079
Its a lightning link. basically makes your AR-15 full auto with out needed a FA sear. It drops in on top of the trigger group and connects the bolt to the dis connector. Registered ones sell for around 8k when they come up on the market. and they are pretty easy to install and uninstall supposedly making it easy to ditch if you had to i would imagine.

>>58697079
The ATF has determined that a shoelace in a certain configuration is a machine gun.

>>58697079
Turns your raifu from semi-fun to full-fun.

The gubberment doesn't like it because they don't get a

>>58697754
*they don't money from the massive tax

>>58696876
This doesn't even work since you used lossy compression

>>58697754
>because they don't get a
already? damn they got faste

>>58696876
too bad shitty jpg broke everything

File: 1481074707095.jpg (76KB, 640x573px) Image search: [Google]

76KB, 640x573px

>>58696954
I remember downloading cracked version of Honorbuddy(wow bot) from a website. There was a image on the website that when you saved it as a zip file it contained the bot. I thought it was pretty cool.

File: 1483100247987.jpg (27KB, 640x638px) Image search: [Google]

27KB, 640x638px

>>58697797

File: 1437742124956.jpg (165KB, 669x562px) Image search: [Google]

165KB, 669x562px

>>58696876
tfw you remember whole threads of .pdf ebooks that were uploaded as images (.gif?) on oldfag era /b/

>>58697754
They don't like it because it is a NFA item. And the tax they don't get? I don't know if a $200 transfer tax stamp is what I would call massive.

>>58697754
Aaand showah'd

>>58697688
Explanation and link plz.

>>58700449
I wish they would perform the surgery on that person. It wouldn't do anything to stop the epidemic stupidity, but at least one person would suffer for it.

>>58701640
If you use a shoe string and a servo for fullauto that counts as a machine gun instead.

>>58696876
Cool picture, saved
Not encryption and yeah this can be done for anything. This was made to share a 3d printer file as an image. It's probably from librechan.

>>58696876
>>58696954
this, and in this specific case;
png (which the original file was) files store pixels starting from the upper left, and ending at the lower right
while bmp files store them starting from the lower left, and ending at the upper right, and the pixels are stored raw, with a small header at the beginning

this is why the "noise" (data) is at the bottom, bmp places the bottom of the image at the start of the file
7zip and winrar are capable of ignoring the bmp header to find their own magics (bytes that signify that a piece of data is a particular format)

File: C2o2nt4UUAEBNRP.jpg (250KB, 918x1200px) Image search: [Google]

250KB, 918x1200px

>>58696876
>encryption
/k/ is adorable

File: a.png (3MB, 1636x1491px) Image search: [Google]

3MB, 1636x1491px

>>58703584
here's a functional copy

on linux you can use;

$ convert -depth 8 -alpha off in.png out.bmp
$ 7z x out.bmp

>>58703698
GNU/Linux*

>not storing your weapon parts in mp3's

https://jii.moe/rJt2q8swx.mp3

ffmpeg -i in.mp3 -f wav - | minimodem -rR 32000 -f - 2400 | base64 -d > out.7z 

>>58696876
Stenography as another anon pointed out.

The way it's done is some image files contain a end of stream marker (or file length) in the header. So instead of trying to use the whole file, it uses the bits of it that it needs (which is typically the whole file)

Zips are a little fucked though. All the data is stored in the front end of the file and at the very end a index/file list is stored with the relative offsets of various files.

So if you have a jpeg, slap a zip to the end of it and upload it somewhere that doesn't resize it or fuck with it you have a multipurpose file!

This is also how self extracting exes are a thing

>>58703964
you described concatenation, which is not related to op's picture nor stenography

>>58703758
GNU plus Linux*

>>58703964
>>58703981

>stenography

It's steGANOgraphy you brainlets. Stenography is a form of shorthand writing.

>>58703758
even just "linux" was too strict, neither imagemagick nor 7z are linux or gnu-specific

File: a.png (61KB, 209x251px) Image search: [Google]

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>>58704001

>>58703964
>my favorite tech youtube vlogger explained some shit to me and I still dont understand, look how smart I am guys teaching you something i dont know what the fuck im talking about

File: !.png (305KB, 532x441px) Image search: [Google]

305KB, 532x441px

That looks like Cornelia.

>>58704021
>Hey I read some shit forever ago and am not autistic enough to give a fuck about how the specifics of the ZIP format work
>Better not take a stab at it in case I look retarded

Fuck you.

>>58704097
"explaining something to someone" is not a good time to be "taking a stab at it"

>>58704140
It's better than nothing when someone is seeking information.

>>58704040
Related.
https://a.pomf.cat/edyzbp.webm

>>58704145
i'd say no information is better than bad information

>>58704187
bad any information leads to further investigation for seeking the truth

>>58704238
only if you mention that you aren't sure
and your information wasn't even relevant in the first place

/k/ is worse than /pol.

>>58704254
idiots won't improve anyway anon

>>58704263
that does appear to be the case

>>58700449
No, but I remember 4chan being flood with some bullshit pics and instructions to save those as .bat files and run 'em.
Some crazy stuff, if you ask me.

>>58704347
Someone already posted a rundown if you're curious.

http://wiki.linuxquestions.org/wiki/Embed_a_zip_file_into_an_image

>>58704347
that was different; there were delete system32 bats, but the incident you mean was probably Snowcrash. If the user saved a crafted image as .js and ran it, it was a virus that would post more copies of the image. 4chan was overrun for a few days because people are fucking retarded as fuck.

>>58697609
so its an illegal mod?

Would you need a metal mill to make one of these?

>>58705056
I mean, ABS would probably do, in a pinch, for a while.

>>58704750
Yes. You can get legal ones that were manufactured and registered before a certain date, provided that you pay an extra tax and jump through shittons of background check/bureaucratic bullshit. But making or even possessing one without doing the paperwork is a felony.

>>58704661
Yep, I remember all the solid-color squares. Pretty brilliant desu. Damn captcha ruining all the fun.

>>58704661
This method hasn't worked on 4chan for quite some time.
https://encyclopediadramatica.se/Embedded_files

>>58704661
>>58705159
Ah yes.
Thanks for clearing this.
And it was pretty darn hilarious.

>>58705177
There was a moment when mute boards had sound embeds for pics and some 4chanX forks/addons that could play them were common.

>>58705198
>mute boards
I thin it was before enabling sound for /gif/ and /wsg/, though

>>58705177
OP didn't ask, "how do I do this on 4chan"

>>58705198
I saw a sound thread on /a/ not to long ago.
Sound extensions are still being updated.

>>58705207
Still prevents confusion.

>>58705221
I remember bans being issued for posting embedded music.
Ah well.

>>58705077
Ah I see.

File: 1476879268335.gif (652KB, 500x281px) Image search: [Google]

652KB, 500x281px

This type of file is known as a "polyglot.". See PoC||GTFO for more info on advanced polyglots.

>>58703529
So the real thing is "the atf has determined that a semiauto gun modified to be full auto with a servo and a string is a full auto gun". Not "a shoelace is a machine gun".

Makes sense to me now. Thanks.

>>58705766
no, actually the come-off is "a device, no matter how simple, capable of converting a semi-automatic into a full auto is subject to the same legal restrictions as a full auto weapon itself"

>>58696954
basically explains it the best possible way

the issue with sticking stuff in an image and putting it on the internet is compression
if that image gets compressed, you may lose the ability to convert it back to a zip file

which it looks like it already has
finding a source image may be difficult
even though a lightning link can be found a bunch of other ways, or you can just measure out the link dimension requirements for your firearm and make one
though even then, the idea of taking a semi auto rifle and going full fun mode really isnt smart or practical
you can go to jail for owning it, you cant fire it anywhere outside of ranges that allow full auto, or a private range, and its expensive to magdump

steganography is much more useful for a form of "blind security" when transferring information physically, like a bunch of those images on a usb stick, and you want whoever looks at it to see images, but then someone who knows what they are can get the actual data out of them, music, porn, death ray plans, whatever

>>58705923
So "a shoestring and servo configured to make a semiauto gun into a full auto gun is subject to the same restrictions as a full auto gun itself". I understand it better now.

Whats this servo thing? Are there currently-sold guns that can go full auto with just a string or is more always required?