UPX-UCL

UPX-UCL, based on the UCL library licensed under GPL, compresses executable files to minimize disk space, network load, and download times. It is particularly useful for shrinking binaries in penetration testing, malware analysis, or software distribution where size matters. The tool can compress various formats including DOS, Linux/ELF, and Windows PE files.

Use cases include preparing payloads for exploitation by reducing their footprint, analyzing packed malware by decompressing it, or optimizing tools for deployment on resource-constrained systems. The package installs as a standalone binary with minimal dependencies.

This version (UPX 4.2.4) provides options for fine-tuned compression, decompression, and handling specific file overlays or formats, making it versatile for reverse engineering and binary manipulation tasks.

UPX-UCL uses the UCL compression library to shrink executable files by applying advanced algorithms like NRV or LZMA, preserving executability for direct runtime decompression. It processes PE, ELF, Mach-O, and other formats by analyzing sections, compressing code and data while handling relocations, exports, resources, and overlays. Decompression reverses this, restoring the original file. Specialized options manage format-specific elements like build-IDs, icons, or DOS headers for compatibility across architectures (amd64, arm, etc.).