Stack Overflow
Stack Overflow

Questions tagged [upx]

UPX (Ultimate Packer for eXecutables) is a executable packer that is used to compress executable files.

UPX is a portable, high-performance executable packer for several different executable formats, includes support for Windows and Linux executables and DLLs. It achieves an excellent compression ratio and offers very fast decompression.
It is an open-source project.
For more information and downloading the software you can check this link

48 questions
43
votes
13 answers

Are there any downsides to using UPX to compress a Windows executable?

I've used UPX before to reduce the size of my Windows executables, but I must admit that I am naive to any negative side effects this could have. What's the downside to all of this packing/unpacking? Are there scenarios in which anyone would…
Mick
  • 13,248
  • 9
  • 69
  • 119
15
votes
1 answer

Executable made with pyInstaller/UPX experiences QtCore4.dll error

A python program, which I compiled with pyInstaller, turned out to be over 400 MB. The program's GUI is based on htmlPY, which is "a wrapper around PySide's QtWebKit library." The large size of the program partly owes to the fact that it utilizes…
Boa
  • 2,609
  • 1
  • 23
  • 38
14
votes
3 answers

How to detect what was the PE packer used on the given exe?

I've found an application which seems to be packed. I opened it with some hex editor and it contains "UPX1" section and "3.00 UPX!" string. Unfortunately I'm not able to decompress it with upx latest, it says "not packed by UPX". Is there a way to…
migajek
  • 8,524
  • 15
  • 77
  • 116
13
votes
1 answer

UPX NotCompressibleException

I recently do some study about executable compression. When compile the test.c C language source and compress it with UPX in Linux not windows. It is list in Terminal: UPX: test.so NotCompressibleException. The source code of test.c is: int main(){ …
QianBin Piao
  • 271
  • 1
  • 2
  • 10
7
votes
1 answer

Boost thread and UPX compression == not valid win32 application?

When I just declare boost::thread t1, t2; in my program and then compress .exe file with UPX, the compression succeeds. But when I try to launch the compressed exe, Windows tells me that it's "not valid win32 application". There is a bug report…
Sergey
  • 19,487
  • 13
  • 44
  • 68
6
votes
1 answer

what is UPX's best compression method

I Have been trying out different EXE packers recently. I tried out ASPack, UPX, mPress etc.. While trying out half a dozen packers, i observed that most of the packed EXE's can trigger false virus signatures. Even UPX is no exception. Still, my…
jimsweb
  • 1,082
  • 2
  • 17
  • 37
6
votes
5 answers

Method to determine if an exe file has been compressed with UPX

Is there a method to determine if an exe file has been compressed with UPX? The function to determine if an exe file has been compressed is excellent except I found a problem with the code. If the function IsUPXCompressed is called then you try to…
Bill
  • 2,993
  • 5
  • 37
  • 71
5
votes
1 answer

Why does my application use more memory after I compress it with UPX, and what can I do about it?

I'm using the UPX compressor to compress my application written in Delphi XE. The file size goes from about 32 Mb to 8 Mb. The strange thing I noticed, though, is that the occupation of the RAM increases significantly when running the compressed…
Enzo Costantini
  • 167
  • 1
  • 9
5
votes
1 answer

Does UPX magically transform binaries from dynamically linked into statically linked libarires?

I'm trying to build a qt-based software with static libraries on gnu/linux amd64 without success (qt is successfuly statically built). Now i see that some people are using UPX. So i tried on a dynamic built and, indeed, the 'file' command recognizes…
user3129066
  • 51
  • 3
5
votes
0 answers

Is it possible to pack native binaries (built for ARM) of Android app with UPX?

The latest Windows UPX version 3.09w throws UnknownExecutableFormatException, so it apparently doesn't support Android .so binaries for ARM. Are there any UPX forks for Android?
Violet Giraffe
  • 32,368
  • 48
  • 194
  • 335
4
votes
0 answers

Reducing executable file size with UPX in macOS

I am creating a bundled app with PyInstaller. The app includes numpy so the final size of the bundled app is > 600MB. I want of course to compress the size of the bundled app so I installed upx via brew install upx. However, PyInstaller crashes with…
kbr85
  • 1,416
  • 12
  • 27
4
votes
1 answer

is it OK to use compressed dll(s)?

I really lack experience on developing things on Windows, and I may have missed some obvious things, try to stay calm :) I have an application (Qt C++) which uses some .dlls from its own path (I mean I deliver those .dlls along with the .exe). When…
destan
  • 4,301
  • 3
  • 35
  • 62
3
votes
1 answer

Pyinstaller not building correctly with PyQt5

I've been trying to build a project using pyinstaller. The project is using PyQt5 and I'm not able to build it correctly. UPX and python are in my PATH. I don't want to mess with any of the package python files so I'm not sure what to do. Here is…
Tenze
  • 47
  • 1
  • 5
3
votes
2 answers

Checking if an ELF is packed with UPX in Linux

I have zero knowledge of how the ELF format works or how to access its headers and data via code, however I need to check whether an ELF binary has been compressed (packed?) with UPX for Linux. Checking the binary with strings I saw the string UPX!…
Jessica
  • 2,005
  • 4
  • 28
  • 44
3
votes
3 answers

Are there any executable packers (like UPX) for iOS?

Just wondering. Or is it even technically impossible to write me, e.g. because iOS may prevent jumps to the area where the unpacked code resides?
MrMage
  • 7,282
  • 2
  • 41
  • 71
1
2 3 4