Questions tagged [malware]

Malware, a portmanteau for malicious software, is software used or created by attackers to disrupt computer operation, gather sensitive information, or gain access to computer systems.

Filter by
Sorted by
Tagged with
119
votes
14answers
108k views

Where can I, as an individual, get malware samples to analyze?

It seems that a popular use of software reverse engineering skills is to reverse malicious code in an effort to build better protection for users. The bottleneck here for people aspiring to break ...
67
votes
9answers
62k 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'...
63
votes
4answers
4k views

How can I analyze a potentially harmful binary safely?

I've recently managed to isolate and archive a few files that managed to wreak havoc on one of my client's systems. So I was wondering what software and techniques make the best sandbox for isolating ...
5
votes
1answer
2k views

Intro to reverse engineering [closed]

I would like learn how to reverse engineer malwares. I have a very small experience reverse engineering windows applications. I would like to know if there are good resources that is helpful in ...
13
votes
4answers
3k views

Debugging malware that will only run as a service

I'm trying to debug a malware sample that installs to a system as service and then will only start if it starts as a service. Other functions are still available without the service start, like ...
13
votes
2answers
8k views

What are the different types of packers?

I know the basic principle of a packer. Basically, it is a small routine launched at the beginning of the program that decompress the actual program and jump to it once achieved. Yet, it seems that ...
2
votes
2answers
4k views

Where can I get Linux malware samples?

There have been numerous sites stated in this wonderful post that one could retrieve malware samples. However, I am having a difficult time (sorry D:) locating Linux-specific malware from those sites ...
3
votes
1answer
403 views

How can I determine if a piece of code is an encryption algorithm?

I am trying to reverse engineer a malware, and came across a piece of code that I suspect is an encryption/decryption procedure, however I do not know for sure. I can recognize that it extracts its ...
9
votes
3answers
2k views

Why is JMP used with CALL?

I am trying to analyze an old malware sample in OllyDbg. It has instruction of the format CALL <JMP.&KERNEL32.SetUnhandledExceptionFilter> I am not an expert in Assembly. I know that CALL ...
4
votes
2answers
366 views

Why does an executable give an error when opened in $tool?

I have an executable that runs in the operating system, but when when I open it in $tool I get an error. What is going on?
19
votes
4answers
5k views

How common are virtualized packers in the wild?

I'm just getting into the RE field, and I learned about virtualized packers (like VMProtect or Themida) in a class about a year ago. How often is malware in the wild really packed with virtualized ...
5
votes
3answers
3k views

Is learning assembly enough to become a malware analyst? [closed]

I am a C/C++ developer and I have started learning assembly language programming with the goal to become a malware analyst. I know it is not enough to just know how to read assembly to become a ...
13
votes
3answers
15k views

Difference between DllMain and DllEntryPoint

I have a piece a malware I was share with. (I do this for fun, anyways) Is a DLL according to the IMAGE_FILE_HEADER->Characteristics. I was trying to do some dynamic analysis on it. I have done the ...
14
votes
5answers
3k views

How to capture an “in-memory” malware in MS-Windows?

I have an infected MS-Windows 7 machine with an in-memory malware, shutting it down will probably make it disappear and I would like to get the malware in a more convenient format to perform some ...
13
votes
4answers
4k views

INT 2D Anti-Forensic Method

Inclusion of an INT 2D instruction appears to be a fairly common anti-debugging tactic used by Windows malware authors. From what I understand, it causes a process to act differently when a debugger ...
5
votes
3answers
2k views

Where can I find benign samples with a high potential to false positive?

In the pursuit and development of malware detection algorithms, often a big sample set of both malicious and benign samples is required. Both machine learning or similar automated techniques, as well ...
11
votes
5answers
2k views

Malware in virtual machines

Once I perform static analysis on a malware sample, I next run it in a virtual machine. Does this give the malware a chance to spread to the real machine? Does this give the malware a chance to ...
-2
votes
1answer
775 views

How do anti-virus programs catch a virus? How they detect it? [closed]

I need to know how anti-virus programs catch malware. Do they do it with hash numbers or not?
9
votes
2answers
6k views

What are the differences between metamorphic, oligomorphic and polymorphic malware?

Malware use several methods to evade anti-virus software, one is to change their code when they are replicating. I saw mainly three type of techniques in the wild which are: metamorphic malware, ...
4
votes
2answers
221 views

Analysing malware in a real environment (non-virtual environment)

I have analysed malware previously using Cuckoo Sandbox, however, I've seen that some malware won't run as they detect they are actually running in a virtual environment (they implement some anti-...
-4
votes
2answers
3k views

Anti-debug techniques for MS-Windows?

Is there any anti-debugger tricks used by malware other than interrupt INT 0x2D ? And, how do they work ? Working examples would be really nice !
5
votes
1answer
2k views

How tools like PEiD find out the compiler and its version.

How tools like PEiD and CFF explorer find out the compiler and its version. I am analyzing a executable file. Which shows: Borland Delphi 3.0 But the section names .text .rsrc. Which is usually ...
3
votes
1answer
861 views

Good foundation for reverse engineering malware

I have been intrigued by reverse engineering recently and just finished Paul Carter's PC Assembly Language book (http://pacman128.github.io/static/pcasm-book.pdf) which was a great primer for x86. My ...
4
votes
3answers
283 views

Tool for checking if there is any patch in the loaded module

I'm looking for a tool that is able to check loaded module for any placed patches even on not exported functions. I'm aware of Gmer, RKU and Co. and frankly I don't really trust their results.
3
votes
2answers
2k views

Reversing a Windows service

I am trying to reverse engineer a malware that open a windows service dynamically in OllyDbg. When the malware calls StartServiceCtrDispatcherW, I receive an error: How I can continue to analyze ...
2
votes
2answers
1k views

Generating call graph for assembly instructions

I'm writing a tool and I need to generate the callgraph for assembly instructions. But I do not know how to exactly generate call graph from assembly instruction. Do you have any idea? To clarify, I ...
8
votes
2answers
1k views

Is there an easy way to detect if the SSDT has been patched from a memory dump?

The SSDT is a dispatch table inside the Windows NT kernel, and it is used for handling calls to various internal kernel APIs. Often malware will change addresses in the SSDT in order to hook certain ...
7
votes
2answers
2k views

Virus uses a custom XOR encryption and need help possibly cracking it / Reversing EXE

As stated in my previous question i was infected by a encrypting virus that encrypts two 1024 byte blocks of any given file (First 1024, and last 1024) in some type of custom CFB XOR encryption. I ...
3
votes
3answers
3k views

Detecting packed 64-bit Windows Portable Executable (EXE) files

What programs are the most useful to detect if a 64-bit PE file has been packed (main focus is on EXE files). I am not interested in the packer used I would just like to know if the file is packed or ...
2
votes
1answer
901 views

Dump a child process created by malware with an ALTERNATIVE process hollowing process

I'm reversing a malware which uses a variant of Process Hollowing to create a process which I can't dump. I don't know what I'm doing wrong. I always see the suggestion to stop at GetContextThread , ...
1
vote
3answers
2k views

How can I export only the opcodes from objdump (or any other program)

I have multiple malware files, I want to do an analysis with the opcodes. Im able to export everything to text but I only need the middle column. Any idea on how can I solve this? In other words of ...
0
votes
3answers
239 views

Most efficient way to begin analyzing malware binary

I'm taking a reverse engineering course and the class has just been given a big project where we have to analyze a packed malware binary. I am using a Windows 10 VM. I am a little confused on where to ...
0
votes
0answers
44 views

IDAPython - Find the start of an undefined code blob

I'm currently working on an IDAPython script that aims to remove various rogue-byte from the malware that I'm reversing. I'm in a case where some portions of my code contain this type of anti-...