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Questions tagged [deobfuscation]

Techniques to remove obfuscation from a piece of program.

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93 votes
9 answers
317k views

How do I reverse-engineer .so files found in Android APKs?

I know how to reverse-engineer normal Android APKs using tools like apktool and dex2jar, but I don't know how to work with obfuscation. When I extract everything from APK, I get some Smali files (I ...
Pervy Sage's user avatar
  • 1,205
76 votes
9 answers
86k views

Analyzing highly obfuscated JavaScript

I was recently analyzing a web page that contained some highly obfuscated JavaScript - it's clear that the author had went through quite a bit of effort to make it as hard to understand as possible. I'...
Adam Caudill's user avatar
63 votes
7 answers
135k views

What is a good Java decompiler and deobfuscator?

I am using JD-GUI to decompile Java JAR files, but the problem is that it leaves many errors, such as duplicate variables which I have to fix myself and check to see if the program still works (if I ...
23 votes
4 answers
8k views

What is "overlapping instructions" obfuscation?

I analyzed some binaries in x86/x86-64 using some obfuscation tricks. One was called overlapping instructions. Can someone explain how does this obfuscation work and how to work around?
perror's user avatar
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16 votes
1 answer
125k views

How to deobfuscate an obfuscated javascript file like this? [duplicate]

I'm having serious problems deobfuscating a JavaScript file at work. This file is inside a web app that I was left in charge to improve it. The problem is that I can do it without having access to ...
MaizerG's user avatar
  • 169
11 votes
4 answers
24k views

Try to deobfuscate multi layered javascript

According to the techy zilla blog It will be much harder to deobfuscate code that has been obfuscated using multiple obfuscating algorithms. According to them, jsbeautifier can't fix this obfuscated ...
user101579's user avatar
11 votes
3 answers
7k views

What are the available libraries to statically modify ELF executables?

I would like to be able to rewrite or reorganize an ELF binary program directly from the executable format (not at compile-time). The only library I know to do this is elfesteem (used in Miasm). But,...
perror's user avatar
  • 19.1k
9 votes
3 answers
13k views

Guessing CRC checksum algorithm

I am trying to reverse engineer a 16 bit checksum algorithm of one relatively old (10 years) LAN game that is no longer supported nor has source code available. As it seems, data packets don't have ...
astralmaster's user avatar
7 votes
1 answer
2k views

How can I decode this php code?

I found this backdoor on a client's website. http://pastebin.com/wVs8w44v (original format) http://pastebin.com/acfx49QJ (semi - readable) I have gotten rid of it and realise it's an obfuscated ...
Vikas Thakur's user avatar
7 votes
2 answers
7k views

How to find file compression or obfuscation type

The program I'm trying to decompile uses several supporting files: somesound.mp3 someimage.jpg etc.. The files are all located in the file system, not embedded into the exe. The files are used at ...
Drahcir's user avatar
  • 171
6 votes
1 answer
2k views

How to efficiently simplify obfuscated formula in QF_BV logic with Z3?

I would like to know if there are efficient ways to simplify arithmetic formula expression over bit-vectors with Microsoft Z3. But, first, I would like to explain a bit the problem. Lets start with an ...
perror's user avatar
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6 votes
1 answer
771 views

Simplifying assembly

I'm analysing some binary trace, it's pretty much obfuscated. What I need to do is to understand work flow of its alghoritms. However I cannot find any reliable tool which would help me with that. I ...
kozera2137's user avatar
6 votes
1 answer
724 views

Recompiling/optimizing redundant code to make analysis easier

I'm analyzing an application created with Borland Delphi but the poor quality of the object code makes analysis difficult and tedious. The code is so convoluted and inflated with superfluous ...
Eric's user avatar
  • 439
5 votes
2 answers
454 views

Formal obfuscation

My question is related to this question with the excellent answer of @Rolf Rolles. Since the paper of M.D. Preda et al is quite technique so I wonder whether I understand their idea or not. The ...
Ta Thanh Dinh's user avatar
5 votes
2 answers
316 views

Need help in figuring out checksum used in this small wireless packet

Need help in figuring out the checksum used for this small data packet. Packet is 48 bits long, I already have figured out most of the bits. Least 8 bits change even if there is a single bit change in ...
chis's user avatar
  • 51
5 votes
2 answers
5k views

Dealing with heavily obfuscated Java, possibly on bytecode level

I've got a jarfile from a friend, he told me to put it thru an decompiler. So I did, but: JD-GUI basically spit out just the imports and didn't show any class data CFR dumped out stack trace on ...
Kamila Szewczyk's user avatar
5 votes
1 answer
2k views

IDA PRO Hex-Rays 1.5 pseudo code understanding -=0x3FFFFFFFu; += 0x3FFFFFFFu;

I'm trying to clean up the pseudo code to make it compile and function similar if not exactly the same as the original code. This bit which looks like this appears in various places I'm trying to ...
SSpoke's user avatar
  • 759
5 votes
0 answers
15k views

Deobfuscating Unknown C# obfuscator?

Hello, I am having an exe file that I am trying to deobfuscate and debug using dnspy. The exe file was written in C# and obfuscated with unknown deobfuscate according to de4dot! I tried to all my ...
mo5br's user avatar
  • 51
5 votes
1 answer
2k views

Understanding AutoIT "compilation"

I'm trying to de-compile a cheat created for my game so I can fix it. The problem is the version used is 3.3.14.2 which no longer has official de-compiler support. I have tried looking for 3rd party ...
majidarif's user avatar
  • 235
4 votes
3 answers
9k views

Extracting classes from running JVM

I'm trying to RE a Java application that uses an obfuscated loader program to load classes from a second, obfuscated archive-like file. I'm trying to get at these loaded classes for further analysis, ...
nickanallen's user avatar
4 votes
3 answers
416 views

Obfuscated code analysis - can unused variables be ignored?

I am analyzing a malicious javascript. The code is encoded and obfuscated in a way that I did not manage to even partially deobfuscate yet and it is filled with long strings. In order to simplify the ...
skooog's user avatar
  • 197
4 votes
2 answers
767 views

What's this obfuscation technique?

I'm reverse-engineering a particular dylib on Mac OS X. The dylib is highly obfuscated, but I suspect it's from some well-known technique that I'm not aware of. I'd like to describe it in the hope ...
user27283's user avatar
4 votes
1 answer
902 views

Protect a key from being recovered by decompilation

I work in a game editor that develop an online game. In our endless struggle against bots (that have negative impacts on server performances, game economy, game experience, ...), one of ours weapons ...
Kriss's user avatar
  • 41
4 votes
1 answer
863 views

On the indistinguishability obfuscation (informally)

I have some superficial thinking about the indistinguishability obfuscation, these come from this question of @perror and the answer of @mikeazo herein about a construction of the indistinguishability ...
Ta Thanh Dinh's user avatar
4 votes
2 answers
2k views

Automating pattern-based de-obfuscation of x64 code using IDA plugins

Trying to deobfuscate x64 code. You can skim/skip most of this, since it mainly exists to prove I have tried and exhausted all avenues. Burning Purpose To massively automate the deobfuscation within ...
Orwellophile's user avatar
4 votes
1 answer
7k views

Analyze obfuscated JavaScript code? [duplicate]

I have this code var _8818;var _7347='...
user3011405's user avatar
4 votes
0 answers
65 views

Decyphering 8kbps audio file format used in Solar Chanting Lotus

I'm trying to reverse engineer a solar powered chanting lotus flower so that I might replace the built in audio with something more interesting. The main chip (JL16B-083A - haven't been able to find ...
Captain Lavender's user avatar
4 votes
0 answers
90 views

Decrypt Keybindings for EVE Online

I've had this idea for a while for a tool I'd like to make to assist people in getting used to keybinds in EVE Online. Not sure how useful it'd actually be, but seems like a fun project nonetheless. I'...
Dealman's user avatar
  • 41
4 votes
0 answers
10k views

Reversing Pyarmor Discussion

Anyone messing around with pyarmor recently? For those of you that are unaware of what pyarmor is, its a protection software that is to help obfuscate and protect your software. Heres an image of what ...
Jimmy Hankey's user avatar
4 votes
0 answers
2k views

How to decompile a obfuscated mach-o dylib?

I am trying to decompile a dylib called libConfigurer64.dylib, which is loaded from the environment variable "DYLD_INSERT_LIBRARIES" I want to analyze what it really does, so I dragged it in to IDA,...
Jemmy1228's user avatar
  • 141
3 votes
2 answers
998 views

Guidelines for dealing with obfuscated code

I have taken a deep dive into reversing software with IDA, I used Ghidra before. I have already solved a couple of basic crackmes now I have targeted another one which's code is obfuscated, also has ...
geo10's user avatar
  • 145
3 votes
2 answers
151 views

Hardcoded addresses in dumped PEs

I have taken a dump of a game using Explorer Suite, and while looking at some obfuscated parts of the game PE's text section in IDA, I've seen code that follows this form: mov rbp, 7FF633CE2790h jmp ...
P. Private's user avatar
3 votes
1 answer
3k views

Rename classes and packages in a jar file

I have an obfuscated jar file I'm trying to decompile and get into an eclipse project. I can easily view the "source" using a tool like jd-gui but I cant save it because the filenames are too long. I ...
Ephyxia's user avatar
  • 31
3 votes
2 answers
4k views

How to reverse engineer an exe built using nexe?

I am working on an express application. I obfuscate the source code using javascript-obfuscator. I am using nexe cli for generating a single exe from the obfuscated code. Can anyone tell me if there ...
Krish's user avatar
  • 31
3 votes
1 answer
1k views

De-obfuscating code ran through JScrambler 3x via Eval() functions

I am relatively new to JS and de-obfuscation in general and I am having difficulties reversing some complicated JS. I know the code itself is obsfucated via jscrambler 3-4x and therefore is ran ...
Impensus's user avatar
3 votes
1 answer
2k views

How to deal with heavy control flow flattening?

I am trying to reverse engineer an executable that uses a lot of control flow flattening obfuscation (i.e, lots of subroutines that end with something like jmp esi, jmp eax) IDA Pro isn't able to ...
Jeremy's user avatar
  • 263
3 votes
1 answer
441 views

Experiences from reverse engineers in detecting recursive calls

I have absolutely no experience in reversing real-world binary codes, so I wonder how the obfuscated codes prevent reversers. I doubt that the reverses always find some ways to understand what are ...
Ta Thanh Dinh's user avatar
3 votes
0 answers
1k views

How can I practically approach VM-obfuscated code with symbolic analysis/execution?

Dealing with VM-obfuscated code and started learning about symbolic analysis but having a hard time wrapping my head around how to practically apply it to a problem. If someone can give me some ...
patchrail's user avatar
  • 143
3 votes
0 answers
977 views

How to use Ghidra to work with VM obfuscated binaries?

By "VM obfuscated binary", I mean a binary that contains one or more implementations of a VM internally, and also some bytecode that can run on this VM. One of the reasons why this binary is this way, ...
auspicious99's user avatar
3 votes
0 answers
3k views

Deobfuscate PHP that contains - goto

I've found a bunch of obfuscated PHP scripts in my server but it seems I cannot deobfuscate them to follow the code flow. I came to the conclusion that the files have been obfuscated with https://www....
Viktor Joras's user avatar
3 votes
0 answers
3k views

Tool for JavaScript deobfuscation

I'd like to reverse engineer a JavaScript program by manually renaming minimified variable, parameter and function names. However, updating my reverse-engineered code to a newer version would be very ...
user avatar
3 votes
1 answer
859 views

Reversal of unknown obfuscation or encryption with known plaintext

Introduction For academical reasons I am reversing a firmware for an embedded device. I have already created a perl script which is able to parse the firmware structure and extract files from it (its ...
SeWe's user avatar
  • 39
2 votes
2 answers
3k views

Virtual machine code obfuscation implementation details

I want to implement a VM based simple proof-of-concept obfuscator. It should take an exe file as input and produce a new pe file with appended vm section. For simplicity let's say the exe file is ...
Rob D's user avatar
  • 123
2 votes
1 answer
1k views

What kind of compression/obfuscation algorithm is this?

I have a couple of streams that look pretty odd within a DICOM file. In a few words, DICOM is very close to what binary XML would look like. Almost all of the information from those DICOM files are ...
tibar's user avatar
  • 375
2 votes
2 answers
1k views

Dealing with obfuscated PUSH PUSH RET instructions

I wanted to run an app on a VM but there are PUSH PUSH RETs stopping me from looking at their anti VM code. There is a messagebox when I run it on a VM. I set a breakpoint at MessageBoxA and it gets ...
nop's user avatar
  • 153
2 votes
1 answer
722 views

Animal Crossing: Pocket Camp .zdat File

Hello I am trying to obtain the music from the new game Animal Crossing: Pocket Camp. The music is contained in files like these: https://download-cdn-ac-pocketcamp.akamaized.net/assets/...
Michael's user avatar
  • 49
2 votes
1 answer
1k views

How to get address where MakeFunction() failed in IDA Pro

I am analysing obfuscated code which contains code paths leading to dummy instructions. These dummy instructions prevent IDA from creating functions. However, I need these functions to do a function ...
nebu's user avatar
  • 61
2 votes
1 answer
2k views

Any good deobfuscators for java?

So I've built an obfuscator for java source code, would anyone know if there is any good deobfuscators which i could test how well my obfuscator is? I know there are many deobfuscators out there, ...
Alan Liang's user avatar
2 votes
2 answers
5k views

Deobfuscating a javascript file

I am having a obfuscated JS file and I want to deobfuscate it (and not beautify it). I have seen answer to a similar question here and I tried de-obfuscating a the file using online version of ...
Pervy Sage's user avatar
  • 1,205
2 votes
1 answer
581 views

Decoding Malware javascript [closed]

My .php and .js files have been attacked twice in a month with some JavaScript code. After going through this similar thread, I ran the JavaScript code posted there and found this decoding result. ...
403 Forbidden's user avatar