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Hacking [release]appx unpacker

Xbox One "Bliss Hack" Open-Source Modchip in Development by GFL_Tech

RainReach · 2026-06-10T21:48:05+00:00

Hey everyone, As many of you saw at the RE//verse conference, researcher Markus "doom" Gaasedelen blew the Xbox One’s security wide open with the "Bliss" exploit—a hardware-level Voltage Glitch Hack (VGH) targeting the secure boot ROM. Because this attack exploits physical silicon behavior during early boot, it is completely unpatchable. While Mark proved the concept, we haven't had a consumer-ready "modchip" to automate this process for regular users. However, hardware developer GFL_Tech has officially stepped up to change that. They have launched an open-source hardware project to design, build, and code a functional physical modchip for the Bliss Hack. I wanted to put together a tracking thread here on GBATemp to log their engineering progress, layout the roadmap, and get more eyes from the HW hacking scene on this project. The Hardware and How It Works Unlike the original Xbox ModXO project, which uses a cheap Raspberry Pi RP2040 to mimic a flash chip, glitching the Xbox One requires insane, sub-nanosecond timing precision. The GFL_Tech modchip is currently leveraging a hybrid approach to tackle the security processor: Signal Processing: Utilizing a TLV3201 high-speed comparator circuit to clean up and track the motherboard's hardware states. Sidechannel Isolation: Designing a custom Quick Solder Board (QSB) to hook directly into the EFUSE lines, tuning resistor values to kill signal noise. The Glitch Trigger: The end goal is using a microcontroller/CPLD setup to automatically sweep timing profiles against the EMMC DAT0 lines to intercept execution flow and drop the voltage rail at the exact microsecond required. The Project Roadmap and Current Status GFL_Tech is treating this as a transparent, step-by-step engineering journey. Here is where the project currently sits: Phase 1: Sourcing and teardown of a 2013 "Day One" Xbox One retail testbed. (Completed) Phase 2: Successful testing of the TLV3201 comparator circuit. (Completed) Phase 3: Finalizing the EFUSE QSB layout and stabilizing pull-up/pull-down noise. (In Progress) Phase 4: Coding the automated glitch-sweep logic for the MCU. (Planned) Phase 5: Real-time timing sweeps against the EMMC lines to hijack execution flow. (Planned) Phase 6: Public V1 Release featuring open-source PCB schematics, code, and installation guides for the community to test and refine. (Planned) Where to Follow and Contribute If you want to look at the hardware schematics, trace their engineering steps, or contribute to the codebase, everything is being kept open: GitHub Source: https://github.com/GFLTech/Xbox-One-Bliss-Hack-GFL_Tech-Modchip- to check out the wiki and hardware roadmaps. Video Devlogs: They are documenting the actual hardware breakdowns, scope readouts, and circuit testing on YouTube under the handle @GFL_Tech. Videos

Thread starter tunip3
Start date Apr 10, 2018
Views 3,297
Replies 5
Likes 1

tunip3

[debugger active]

Banned

Level 9

Apr 10, 2018

hi this just a quick release of an appx unpacker.
it was written in python for version 2.7
you can use it to dump music, models and other stuff that floats your boat
My code may not be clean this was just a quick and dirty implementation that only really touches the wrapper portion not the signature stuff
Im sorry if this is badly written I'm really tired right now

Reactions: KiiWii

KiiWii

Editorial Team

Editorial Team

Level 41

Apr 10, 2018

Awesome! Thank you!

Darksabre72

Blue Falcon

Member

Level 10

Apr 11, 2018

nice release

dominater01

Well-Known Member

Member

Level 12

Apr 11, 2018

the 7z program does the same thing as this

Reactions: tunip3 and Deleted-351540

tunip3

[debugger active]

Banned

Level 9

Apr 11, 2018

dominater01 said:
the 7z program does the same thing as this

I know lol I said before you can get data from appx files treating it as a zip

Last edited by tunip3, Apr 11, 2018

b33tlejuice

Active Member

Newcomer

Level 1

Apr 21, 2018

Windows has a native tool for this too doesn't it? Makeappx.exe? not only packages, but unpackages as well

EDIT: nvm, it's not native to windows 10, but it does come with the windows 10 sdk. think windows 8 has one as well, but its a download from the dev center

Last edited by b33tlejuice, Apr 21, 2018