The "unpacker" is actually built directly into the standard UPX utility. You do not need a separate program; the same tool that packs a file can also unpack it.
UPX (Ultimate Packer for eXecutables) is a high-performance, open-source tool used to compress and decompress executable files across various operating systems, including Windows, Linux, and macOS. While primarily known for shrinking file sizes by 50%–70%, it is also a powerful used by developers and security researchers to restore files to their original state. Where to Download the UPX Unpacker upx unpacker download
: (Optional) Use upx -d filename.exe -o unpacked_file.exe to save the result as a new file without overwriting the original. The "unpacker" is actually built directly into the