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Show HN: I reverse engineered macOS to allow custom Lock Screen wallpapers

cindori.com

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Re: Show HN: I reverse engineered macOS to allow custom Lock Screen wallpapers

#31

Post by 1970-01-01 »

ronsor wrote: post #26
nerdjon wrote: post #5

Worth mentioning that if you want a free way to do this that does not require running additional software. All you have to do is have a video you want to use, download one of apple's through settings, go to the location of the downloaded background (I don't remember where that is right now but a quick google search would take care of this), rename your file to the name of apple's file and then replace it. Mac will ac…

> Until apple starts doing any checksum checks on these files I doubt this method will break anytime soon. Watch as this is used for malware persistence through a code execution exploit. Then Apple will start verifying the file content.

.scr files are untrusted for this very reason.

Re: Show HN: I reverse engineered macOS to allow custom Lock Screen wallpapers

#33

Post by hirvi74 »

cindori wrote: post #21
pm wrote: post #20

What were some of the technical challenges you experienced while reverse-engineering the wallpaper system? I've been reverse-engineering (for lack of a better term) some of macOS' and Xcode's poorly-documented functionality prototyping a personal developer tool. My investigation isn't sophisticated by any means; it's just been trial-and-error, but I haven't found much online in the way of resources for people going d…

Reverse engineering is hard! I use Hopper ( https://www.hopperapp.com ) to disassemble related binaries and frameworks. It's a great way to explore whats actually happening within macOS or Apple apps. You can also export assembly files and throw various agents (Gemini, Claude etc) at them to learn more. It's surprisingly effective!

I'm no pro rev. engineer or anything, but did you try alternatives to Hopper at all? I've never had much luck with Hopper compared to Radare2 and IDA.

Re: Show HN: I reverse engineered macOS to allow custom Lock Screen wallpapers

#34

Post by jeroenhd »

1970-01-01 wrote: post #31
ronsor wrote: post #26

Earlier quoted context omitted.

> Until apple starts doing any checksum checks on these files I doubt this method will break anytime soon. Watch as this is used for malware persistence through a code execution exploit. Then Apple will start verifying the file content.

.scr files are untrusted for this very reason.

.scr files are untrusted because they're plain PE executables. You don't need to exploit anything to get code execution because all they do is execute code.

If they were just video files, they wouldn't be such a vector for malware.

Re: Show HN: I reverse engineered macOS to allow custom Lock Screen wallpapers

#35

Post by jaimehrubiks »

To me it's a bit too expensive for what it provides, so I'll probably not buy it. However I must agree that the hacks on the internet with renaming videos doesn't work very well, and I like the product, so I still wanted to say congratulations, well done.

Re: Show HN: I reverse engineered macOS to allow custom Lock Screen wallpapers

#36

Post by giorgioz »

Hi Oskar! In case you want ideas for future apps for later. https://replacicon.app/ replaces Dock icons...but somehow it doesn't work with the warp.dev icon. I wrote the support and I'm paid customers but they never answered. I really dislike all these AI icons are in black and white! They are very hard to tell apart from each other.

Re: Show HN: I reverse engineered macOS to allow custom Lock Screen wallpapers

#37

Post by 1970-01-01 »

jeroenhd wrote: post #34
1970-01-01 wrote: post #31

Earlier quoted context omitted.

.scr files are untrusted for this very reason.

.scr files are untrusted because they're plain PE executables. You don't need to exploit anything to get code execution because all they do is execute code. If they were just video files, they wouldn't be such a vector for malware.

You still need to priv esc

Re: Show HN: I reverse engineered macOS to allow custom Lock Screen wallpapers

#38

Post by sitzkrieg »

cindori wrote: post #24
Dennip wrote: post #13

What happens to purchasers if/when apple update MacOS and this no longer works?

Apps break on OS updates all the time. I'll do my best to keep supporting this feature. Who knows, maybe Apple will take note and make it a default feature in next macOS?

hoping your business gets eaten alive is a strange wish

Re: Show HN: I reverse engineered macOS to allow custom Lock Screen wallpapers

#39

Post by captaincrowbar »

I like this and would seriously consider buying it - except that the purchase page only has prices in something called "AA$". I have no idea what currency that refers to (AA is Aruba, but they don't use dollars), or how much that might come to in my local currency.
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