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angealbertini.bsky.social
Reverse engineer, file formats expert.
Corkami, CPS2Shock, PoC||GTFO, Sha1tered, Magika...
Security engineer @ Google. He/him.
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Any requests or questions on PDF manipulations ? (Or another format)

ICYDK restrictions in PDF (copy pasting, printing…) are linked to encryption, which often uses an empty user password : no password prompt, but the file is still encrypted. So just decrypting the file (via qpdf, pdftk, print to PDF,…) removes these restrictions.

The livestream on PDF file structure is up. Following the PDF basics livestream, it covers all kinds of PDF structures that you can see in the wild and how to convert them to a classic and accessible form. www.youtube.com/live/9XNdTAP...

Today, the follow-up from PDF basics: What you need to know to edit any PDF. www.youtube.com/live/9XNdTAP...

I just pushed an update to logparse to detect the near-collision blocks (w/ no difference) of TextColl. Thanks Marc! github.com/corkami/coll...

The livestream on multi-hashcolls is up. Covering the hashcoll tag in VT, specific file format structures, defanging files, Stevens' DetectColl, safe hashes... www.youtube.com/live/1D6C6z_...

J’espère bien ! J’aurais l’air de quoi si je n’avais plus que des fichiers normaux ?!

The next livestream will be on mitigating hash collisions: preventing them at format design, filtering them out or detecting them. www.youtube.com/live/A7EBbGv...

The livestream on multi-hashcolls is up! Awesome that David joined and commented on his own hashquines! www.youtube.com/live/-asJnf-...

In 15 minutes… www.youtube.com/live/-asJnf-...

The livestream on crypto-polyglots is up! www.youtube.com/live/RP5PVRU...

In my next livestream, I’ll hexplore crypto-polyglots: - files that remain valid after encryption. - contents that decrypts to different valid content via different keys, with authenticated decryption. www.youtube.com/live/RP5PVRU...

More advanced hash collisions: Shattered++, Lossless jpegs, jpeg as data & image, .tar.gz and Zip+XML (instant Office document collisions). www.youtube.com/live/fCNx2cO...

In the next livestream tonight, we’ll hexplore more advanced hash collisions tricks. www.youtube.com/live/fCNx2cO...

We hexplored the basics of hash collisions and how they can be exploited, exploiting MD5 with Png, Gif, mp4 or Jpg, and also Pdf with SHA1 of course! www.youtube.com/live/wv8aiqW...

In the next livestream, we’ll extend file format tricks to cryptography and abuse hash collisions: www.youtube.com/live/wv8aiqW...

Today, we’ll explore weird files in general (no crypto polyglots or hash collisions, only parasites, mock & polyglots), and how to generate them with Mitra. speakerdeck.com/ange/generat... github.com/corkami/mitra

In 2h, let’s hexplore the PE file format! www.youtube.com/live/eJ1bQmK...

I got Linux running in a PDF file using a RISC-V emulator. PDFs support Javascript, so Emscripten is used to compile the TinyEMU emulator to asm.js, which runs in the PDF. It boots in about 30 seconds and emulates a riscv32 buildroot system. linux.doompdf.dev/linux.pdf github.com/ading2210/li...

@ading.dev hey there! Lovely work on that Doom PDF, I made a livestream about its internals! www.youtube.com/live/t17joAi...

Coming up this weekend: PE & Mitra!

Doom running from the same file on Dos, Windows and Chrome PDF! github.com/angea/doom-p...

Thanks for your attention, it was fun! I crafted a working Doom triglot: Dos executable, Portable executable and PDF. www.youtube.com/live/nG2RZrD...

In 1h!

Coming up next: the .EXE file format!

Thanks everyone! www.youtube.com/live/-6tPcUX...

In ~3 hours, my first livestream on file format designs: www.youtube.com/live/-6tPcUX...

The next livestream will be on comparing the file formats of PNG, GIF and PCX, all lossless image formats and global standards [during their lifetime], so we can focus on the different design decisions and their impact on engineering, parsing & security. youtube.com/live/-6tPcUX...

Today, I'll stream about the PCX format. While it is an outdated and irrelevant format nowadays, its structure and lack of forward-thinking makes it very interesting from a file format design perspective. www.youtube.com/live/0sMRHaN...

My next livestream will be on the .COM files, the DOS "command" file format, the grandfather of PE executables. www.youtube.com/playlist?lis...

I draw my graphics with #Inkscape. My next livestream will be an introduction to Inkscape!

In 1h, let’s hexplore the GIF, an old format full of weirdness ! youtube.com/live/EPaD73O...

Do you know any format or protocol that uses chunking besides Gif/Jif? ICYDK chunking is slicing data in blocks smaller than 256 bytes, with the length before each block. A null block terminates the sequence.

Ce soir, on parle de Doom.pdf !

Le direct d’hier soir sur le JavaScript dans les PDFs.

Ce soir dans 3h, on hexplorera le JavaScript dans les PDFs. www.youtube.com/live/hvixm6C... Le programme prévu est dans la description.