Unicorn Engine VS UTM

OFRAK Tetris is a project I started at work about two weeks ago. It's a web-based game that works on desktop and mobile. I made it for my company to bring to events like DEF CON, and to promote our binary analysis and patching framework called OFRAK.

In the game, 32-bit, little-endian ARM assembly instructions fall, and you can modify the operands before executing them on a CPU emulator. There are two segments mapped – one for instructions, and one for data (though both have read, write, and execute permissions). Your score is a four byte signed integer stored at the virtual address pointed to by the R12 register, and the goal is to use the instructions that fall to make the score value in memory as high as possible. When it's game over, you can download your game as an ELF to relive the glory in GDB on your favorite ARM device.

The CPU emulator is a version of Unicorn (https://www.unicorn-engine.org/) that has been cross-compiled to WebAssembly (https://alexaltea.github.io/unicorn.js/), so everything on the page runs in the browser without the need for any complicated infrastructure on the back end.

Since I've only been working on this for a short period of time leading up to its debut at DEF CON, there are still many more features I'd eventually like to implement. These include adding support for other ISAs besides ARM, adding an instruction reference manual, and lots of little cleanups, bug fixes, and adjustments.

My highest score is 509,644,979, but my average is about 131,378.

I look forward to feedback, bug reports, feature requests, and strategy discussions!

Entails hundreds of hours of single-stepping through that opcode in Linux kernel using an indirect operand pointing toward its own opcode (self-modifying code).

Even the extraordinaire Fabrice Bellard (author of QEMU) admitted that it is broke and did a total rewrite, which fixed tons of other issues.

https://github.com/unicorn-engine/unicorn/issues/364

Macdu (Vita3K dev) also stated that this game is CPU bound so they used a CPU emulator known as unicorn2 , this is also the reason for the slow speed

This is how I found out a snippet of assembly code that can actually distinguished between a KVM hypervisor and most of today’s emulator.

https://github.com/unicorn-engine/unicorn/issues/364

Unicorn is missing from that list.

The python CPU emulator with full program counter (PC) and general (and other CPU-specific) register set controls.

I use it to catch fileless malware in the second fastest dynamic manner. Also good for detecting Rowhammer/SPECTRE behaviors.

Disclaimer: one of the contributors and a contractor that frequently deploy this.

https://github.com/unicorn-engine/unicorn

If you have TrollStore then install the HV version of UTM to try for yourself: https://github.com/utmapp/UTM/releases/latest/download/UTM.HV.ipa

Researching a little showed that this is basically what can be expected running x86 emulation and the systems will just be wonky and slow, although it was running flawlessly, just slow.

There seem to be ways to use Rosetta2 inside a VM [0] to then translate binaries but I found no official support or documentation (using UTM+QEMU that was), this would be such a cool feature, at least there are discussions about it [1,2]

- [0] https://mybyways.com/blog/using-rosetta-in-a-utm-linux-vm-wi...

- [1] https://github.com/utmapp/UTM/discussions/4939

- [2] https://github.com/utmapp/UTM/issues/5460

UTM is open source too though: https://github.com/utmapp/UTM#license

UTM makes it easy to set up and manage macOS and Windows virtual machines. This can be especially useful for developers such as Tauri contributors who need to test their applications across multiple platforms, or for those looking to experiment with different operating systems without affecting their primary system.

If you don't need high performance and want to use the OS only occasionally, check UTM.app, at https://mac.getutm.app/ (or https://github.com/utmapp/UTM ). Free, open source.