From XBOX-SCENE forums

" An anonymous person at the German 23C3 Hacker Congress showed what could be an Xbox360 hack/exploit during one of the 'Lightning Talks'. Lightning Talks is a daily event at Chaos Communication Congress (C3/CCC). It consists in one hour of several short (limited to 5mins) talks.

In a very short presentation a masked 'hacker' showed an Xbox 360 booting up King Kong (the game, by ubisoft). After loading the game a screen pops up showing an Xbox 360 logo, a Mac logo and Tux (the Linux Penguin) and the words "coming soon...". I also noticed a small PCB is hanging out of his Xbox360 and he's using a laptop (Apple Macbook pro?), but it's not really clear what he's doing with it.
Those who followed hacking discussions might remember hackers did some research around the vector shaders in the King Kong demo on the Xbox 360 Kiosk Disc (that ran from recordable media). The demo (and final game too) allow to modify the shaders (they are not checked/signed). However no exploit to take control of the machine was found back then ... so either this hacker found something here, or he's just showing us his custom modified shaders ;)
That's all the details we got for now.

If you don't believe the presentation was really given at 23C3, you can download the +560MB WMV video of the complete 'Lightning Talks' Day4 from the CCC mirrors (direct: mirror1, mirror2, mirror3, mirror4, mirror5, mirror6, mirror7). Forward to the 5th presentation and you'll find it there. However note that the video encoding is far from perfect and the audio seems to be broken/missing. The youtube video below shows just the Xbox 360 presentation, with audio:

UPDATE1! Here are some updates from stuff people posted on our forums.
Here's another footage of the presentation filmed by someone in the public.

Some high-res pictures of the presentation. A bit easier to see that small PCB here. Pictures by Darkman at c3f2m.de:
23C3 23C3 23C3

Also interesting is the official description of the presentation on the CCC schedule site:
[QUOTE]
Title: Consolen Hacking Suprise (XBox360)
Language: German
Speaker(s): Anonym
Description: The XBox360 was live hacked in front of the audience - running Linux and Mac OS coming soon. Stay tuned - a Linux kernel is already booting..
[/QUOTE]
"

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