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Reverse Engineering Snapchat (Part II): Debofuscating the Undeobfuscatable

hot3eed.github.io

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Re: Reverse Engineering Snapchat (Part II): Debofuscating the Undeobfuscatable

#11

Post by masteruvpuppetz »

hackernewsn00b wrote: post #10

Hey OP, since you're here: I find this pretty hard to follow. Would you be open to writing a longform version of this aimed at the tutorial level? Reading between the lines, I would guess you're trying to demonstrate that you really know what you're doing. Maybe as a proof of concept for possible employment opportunities. If so, that's great! Good luck. But if I were interested in reverse engineering some other app,…

+1. Need a simpler version if possible.

Re: Reverse Engineering Snapchat (Part II): Debofuscating the Undeobfuscatable

#12

Post by saagarjha »

hackernewsn00b wrote: post #10

Hey OP, since you're here: I find this pretty hard to follow. Would you be open to writing a longform version of this aimed at the tutorial level? Reading between the lines, I would guess you're trying to demonstrate that you really know what you're doing. Maybe as a proof of concept for possible employment opportunities. If so, that's great! Good luck. But if I were interested in reverse engineering some other app,…

I found it fairly reasonable, although you'd have to have a general idea of the subject beforehand. I read it as a being aimed at reverse engineers who are looking for some general techniques to bypass common anti-debugging/obfuscation features rather than "how to reverse engineer apps 101".

Re: Reverse Engineering Snapchat (Part II): Debofuscating the Undeobfuscatable

#13

Post by wayne »

This level of API obfuscation reminds me of forever ago when MSN Messenger figured out AOL's AIM API, so MSN Messenger could send AIM messages, which annoyed AOL. AOL would make API changes to break MSN, but MSN would update the client and stay ahead. Eventually to make the API uncloneable, AOL changed their payload to exploit a buffer overrun in their own AIM clients that wouldn't be in the MSN clients.

https://nplusonemag.com/issue-19/essays/chat-wars/

Re: Reverse Engineering Snapchat (Part II): Debofuscating the Undeobfuscatable

#14

Post by stephc_int13 »

As someone who wrote similar obfuscators (manually) back in 2003-2006 to protect a few indie games distributed on PocketPC (ARM7/WinCE) I found it quite conforting to see that the techniques are still similar.

I wonder about something, how long did it take?

Re: Reverse Engineering Snapchat (Part II): Debofuscating the Undeobfuscatable

#15

Post by drudu »

hackernewsn00b wrote: post #10

Hey OP, since you're here: I find this pretty hard to follow. Would you be open to writing a longform version of this aimed at the tutorial level? Reading between the lines, I would guess you're trying to demonstrate that you really know what you're doing. Maybe as a proof of concept for possible employment opportunities. If so, that's great! Good luck. But if I were interested in reverse engineering some other app,…

Obviously not the OP but I think that a longform version of this would be an entire book/college level course. I wish I could learn how to reverse state of the art obfuscation in a single, long post but that's just not how it works.

Re: Reverse Engineering Snapchat (Part II): Debofuscating the Undeobfuscatable

#17

Post by spideymans »

wayne wrote: post #13

This level of API obfuscation reminds me of forever ago when MSN Messenger figured out AOL's AIM API, so MSN Messenger could send AIM messages, which annoyed AOL. AOL would make API changes to break MSN, but MSN would update the client and stay ahead. Eventually to make the API uncloneable, AOL changed their payload to exploit a buffer overrun in their own AIM clients that wouldn't be in the MSN clients. https://nplu…

Interesting time that was. I don't believe that any of these internet giants would ship a feature that is effectively a hack, in this day and age.

HTC and Palm also engaged in the back-and-forth, when Palm attempted to get their OS to sync with iTunes.

https://www.wired.com/2009/10/palm-pre-itunes/

Re: Reverse Engineering Snapchat (Part II): Debofuscating the Undeobfuscatable

#19

Post by jonas21 »

hackernewsn00b wrote: post #10

Hey OP, since you're here: I find this pretty hard to follow. Would you be open to writing a longform version of this aimed at the tutorial level? Reading between the lines, I would guess you're trying to demonstrate that you really know what you're doing. Maybe as a proof of concept for possible employment opportunities. If so, that's great! Good luck. But if I were interested in reverse engineering some other app,…

It's easier to follow if you read part I of the series first:

https://hot3eed.github.io/2020/06/18/snap_p1_obfuscations.ht...

Re: Reverse Engineering Snapchat (Part II): Debofuscating the Undeobfuscatable

#20

Post by saltedonion »

wayne wrote: post #13

This level of API obfuscation reminds me of forever ago when MSN Messenger figured out AOL's AIM API, so MSN Messenger could send AIM messages, which annoyed AOL. AOL would make API changes to break MSN, but MSN would update the client and stay ahead. Eventually to make the API uncloneable, AOL changed their payload to exploit a buffer overrun in their own AIM clients that wouldn't be in the MSN clients. https://nplu…

Very interesting. I think this would likely lead to lawsuits today, under a complaint violating DMCA.
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