steg86 is a format-agnostic steganographic tool designed for x86 and AMD64 binaries that enables users to hide information within compiled programs. The tool supports multiple executable formats including PE, ELF, Mach-O, and raw binaries without impacting the performance or size of the modified files. When embedding messages, the binary size remains unchanged and execution speed is not affected. Key features include: - Binary profiling to assess steganographic suitability and capacity - Message embedding capabilities that preserve original binary functionality - Support for various executable formats across different operating systems - Command-line interface with profiling and embedding subcommands - Installation available through Rust's cargo package manager The tool operates by analyzing instruction pairs within binaries to identify locations where data can be concealed. During profiling, it reports the total number of instructions, potential semantic pairs, commutative instructions, and overall information capacity in bits and bytes. For embedding operations, users can input messages through standard input or files, with output typically saved as a .steg extension of the original filename.