Questions tagged [obfuscation]
Concealing the nature of how things truly function or work.
137
questions
0
votes
0answers
44 views
.NET - What kind of obfuscation is this?
I'm currently performing some malicious DLL malware analysis, and I'm having some issues figuring out how to de-obfuscate this particular sample.
It uses a lot of Reflective Assembly calls, and, a lot ...
1
vote
1answer
57 views
Wave File obfuscation
I have this file here, that is supposed to be a wave audio file, but seems to have some obfuscation applied to it. The file header is here: https://pastebin.com/LD5aA1EG Any suggestions where else ...
0
votes
0answers
127 views
What are the known techniques used by wrappers and obfuscators to protect against decompiling?
I am NOT looking to make my application 99% safe, nor my goal is to prevent a a determined reverse-engineer to disassemble it, but simply is to protect my source code from lambda user with little ...
1
vote
0answers
75 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 ...
2
votes
2answers
134 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 ...
0
votes
0answers
75 views
Obfuscated and/or encrypted firmware?
I own 3 samples file of a firmware but I can't determine if it's obfuscated and/or encrypted. Could you give some hint about it? Here is the following samples:
Sample 1
Sample 2
Sample 3
1
vote
0answers
54 views
Trying to replicate encryption of an android app
I was trying to replicate/copy the encryption of an android app which uses CryptoJS with sha256 encryption as having seen in the source code of the android app. fingerprinting the app, it was built ...
0
votes
0answers
49 views
What type is this obfuscation ? (iOS Dylib)
Someone published a patch/crack for my iOS app. I wanted to know what does the dylib but it seems to be heavily obfuscated (all strings are obfuscated too).
You can see some screenshots below.
Can ...
1
vote
1answer
108 views
Reverse Engineering Java - Deobfuscating symbols
I'm new to Java and working on cleaning up a fairly large Java .jar sample where the obfuscator has renamed symbols into invalid names. For example:
import org.lib.00.0.2;
public final class 90
...
0
votes
0answers
31 views
How to call strongly encrypted DLL from Resources?
There is a program. This program accepts plugins. Plugins written with C#. I have to encrypt it. But when I use strong obfuscators I have exception. Program doesn't read. How can I fix that ? How can ...
2
votes
0answers
103 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 ...
-1
votes
1answer
149 views
De-obfuscate JS code [closed]
I came across a script that converts font files from one type to another (i.e. WOFF to TTF, etc).
I would like to understand it and incorporate some of the code into a personal project. The script ...
2
votes
2answers
850 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 ...
1
vote
1answer
179 views
Stack-pointer analysis failed
I'm testing my toy obfuscating C compiler against IDA's decompiler, but IDA refuses always functions (then the decompilation is not possible). For example, at one of lowest-levels of obfuscating, a ...
1
vote
1answer
116 views
Python self decryption script, as mean of obfuscation
I have a software with an embedded python interpreter. The software can open upon startup a given .py script and execute it. Let's assume that in my python environment I can't open other files, and I ...
1
vote
1answer
219 views
Is it possible to completely reverse this code?
i have this code i'm trying to deobfuscate
https://pastebin.com/g5mHpWE4
I used
https://beautifier.io/ and
http://www.jsnice.org/
but the result is still not good, current code:
https://pastebin.com/...
0
votes
1answer
137 views
Error After de4dot - Application Does Not Start
There is an application that has been obfuscation to learn. So in an unpack me style. In the first stage I would unpack with de4dot. After you unpack, the running application stops working.
dump and ...
1
vote
0answers
43 views
Possibly infected image
Long story short I'v downloaded a template for my website and instead of images it has the .html files included, and at the beginning those html files do include PNG IHDR , and they are being loaded ...
2
votes
2answers
308 views
Static analysis obfuscated code
I'm reversing a code that is heavily obfuscated. It uses opaque predicates, call stack tampering, junk code and control flow flattering.
Call stack tampering uses indirect branches (push register / ...
2
votes
1answer
3k views
Best way to protect source code of .exe program running on Python?
I am developing proprietary software that would be distributed in a form of .exe file. In order to use it, users will have to authenticate with their whitelist credentials (username + password).
The ...
1
vote
0answers
74 views
API Hiding Issue
I'm trying to analyze a malware which is hiding API names. When I open it with CFF Explorer, except a few API like GetProcAddress, nothing appears. Basically, I know how API hiding works. I set a ...
0
votes
0answers
47 views
IDA Fails to Analyze Stack Pointer Correctly in Heavily Chunked Functions
I am currently dealing with obfuscated code in IDA.
The obfuscation I am combating is control flow obfuscation, where a function is split up into hundreds of basic blocks spread across the entire ...
1
vote
1answer
101 views
J2ME games obfuscator - Spyro and Tekken 5
While reversing some J2ME games like Spyro or Tekken 5 Mobile I have encountered a weird obfuscation where all fields, methods and classes have names like A, a, B, b, Aa, Bb etc.
It's really hard to ...
5
votes
2answers
484 views
Trace Method Calls in .NET/C# Binary
I have a heavily obfuscated Windows service binary. Fields, types and methods are renamed. While it is possible to decompile the binary using dnSpy, it is still very cumbersome to identify important/...
0
votes
0answers
637 views
Obfuscate JSON file that is served client-side
Through some research I have found that obfuscation won't block hackers from retrieving your .json file, but I'd like to have at least a level of obfuscation that deters some people. I ran into a npm ...
1
vote
0answers
179 views
Mysterious chunk of code in IOLI crackme0x06 challenge
I've been struggling to understand a very strange piece of x86 assembly code from the IOLI crackme0x06 challenge.
Context
But first of all, here is the context : I've successfully cracked the ...
1
vote
0answers
46 views
How to choose a .NET software protector which will have a small impact on run-time performance speed? [closed]
I am writing a .NET software which is doing calculations and drawing in real-time i.e when the user is moving the mouse. I want to protect this software from being reverse engineered and restrict its ...
1
vote
1answer
1k views
How to deobfuscate native Android library obfuscated with OLLVM?
When I load the binay in IDA, all I can see are loads of .datadiv_decodeXXX... functions and this is because of OLLVM. I know it is possible as a Chinese article I found said they were able to ...
2
votes
1answer
159 views
Does a symbolic disassembler exist?
I would like to know if there are disassemblers based on a symbolic analysis, I'm beginner in RE, but I think that a disassembler based on symbolic techniques can be very interesting and could ...
2
votes
2answers
412 views
Jump in the middle trick
I'm reversing a program that "hides" some instructions using the jump in the middle trick. This trick is a jump to a middle of an instruction, whereas the real address actually contains another opcode....
1
vote
1answer
360 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 ...
6
votes
1answer
459 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 ...
1
vote
1answer
1k views
Analyzing and deobfuscating complex JS code [duplicate]
I am looking to reverse engineer a very ugly piece of JS found here.
As far as I can tell, this script generates and sets some cookies on my browser that identify it on the site. Deobfuscating it ...
1
vote
0answers
346 views
C# Hidden Method through transparent proxy object?
I'm dealing with an interesting form of obfuscation. A C# program I am reversing has a central API, let's call it "Central API". This Central API has several functions that aren't exactly defined.
...
7
votes
2answers
450 views
Why do obfuscators remove line numbers, and can I safely leave them in?
Application security engineer here. When we compile our java code, we obfuscate it using KlassMaster and have it remove line numbers (see KlassMaster docs) because of a handwavy explanation "it makes ...
1
vote
1answer
581 views
What is the difference between stripped binary and obfuscated binary
I want to know the difference between stripped binary and obfuscated binary.
1
vote
0answers
1k views
Can de4dot deobfuscate Dotfuscator Professional?
I ran de4dot on a Xamarin app obfuscated using Dotfuscator Professional. However, there's still the random switches and strange ints everywhere. Can de4dot decode this? If not, is there another tool ...
4
votes
3answers
251 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 ...
1
vote
0answers
67 views
Missing Map from Java Native Method to C Code
When writing a C implementation for a native Java method in Android, the rule is to name the C function according to the convention "Java_com_...". But I encountered an APK in which there are no such ...
1
vote
1answer
3k views
Is deobfuscation of my javascript code hard or easy?
I am trying to protect my app code from theft. Since most of it is written in javascript I had to use many obfuscation techniques to make it incomprehensible.
I have written a very small piece of ...
2
votes
0answers
465 views
Obscure router refuses to flash OpenWrt
This is a very obscure Chinese router from a brand called Wavlink. It's the Model: WN529R2/WN529R2P. It's web interface was pretty limited and wouldn't allow firmware modifications.
I found GND/Tx/Rx/...
3
votes
2answers
255 views
Why doesn't this retn instruction return from the function?
I disassembled an exe file on Windows with IDA and saw this function prologue:
I see that when the retn executes instead of returning it jumps to sub_1314cba4.
Why doesn't the retn instruction ...
-3
votes
1answer
9k views
How do I decode this JavaScript code? [duplicate]
Each file starts with the same function:
(function(_0x128f83, _0x1ae5b9) {
var _0x1b5471 = function(_0x339be5) {
while (--_0x339be5) {
_0x128f83['push'](_0x128f83['shift']());
...
1
vote
1answer
509 views
Map an obfuscated javascript file to the original
Among other approaches, there are ways to "prettify" obfuscated javascript. But most of such approaches are geared towards someone trying to understand code that's not their own (e.g. from a website, ...
0
votes
2answers
996 views
verifyError in youtube android app modification
I try to decompile youtube android application and modify it but when I build the application and install on a virtual device faced with below error:
E/AndroidRuntime(1782): java.lang.VerifyError: ...
3
votes
1answer
471 views
IDA pro obfuscation instance
I have tried all the I have learned so far to figure out how to deal with this instance of obfuscation.
So far I understand that an opaque predicate is present, causing an unconditional jump to one ...
3
votes
1answer
626 views
Deobfuscating overlapping x86 assembly instructions
I'm trying to solve a reverse engineering challenge (http://crackmes.cf/users/beatrix/beaba/) and am having trouble with the obfuscation. Below is a piece of code that gets executed almost immediately ...
3
votes
3answers
4k views
Exe protection by TLS callback, trying to understand the behaviour
I have an app, obfuscated by FSG protector. When i tried to unpack it, the first thign that i had is, when i start the process with the debugger/or attach debugger later, i immediatly receive ACCESS ...
0
votes
1answer
613 views
ARM ELF Obfuscation [closed]
Metamorphic is a technique to obfuscate a binary and change the opcode sequence and create new samples with same functionality. In my case, I have some elf binary of ARM processor type and their ...
1
vote
2answers
284 views
reverse javascript crackme encryption method algorithm
This crackme contains a text input element on the screen and a button to validate
The value you enter is set into _inputValue, afterwards you click on a button, the function executes, in the last ...
