# bitdefender/bddisasm

bddisasm is a fast, lightweight, x86/x64 instruction decoder.  The project also features a fast, basic, x86/x64 instruction emulator, designed specifically to detect shellcode-like behavior.

Repository: https://github.com/bitdefender/bddisasm
Canonical: https://ross.abutalabs.com/products/bddisasm
Language: C
License: Apache-2.0
License Family: permissive
Topics: x86, instruction, decoder, x64, shellcode, emulator, disassembler
Last push: 2026-06-29T10:16:07+00:00

## Health v2 (maintenance only)
Score: 74/100 (v2, computed 2026-09-02T17:46:02.011165+00:00)
- activity 90, release rhythm 39, longevity 100
- inputs: {"age_days": 2246, "days_push": 65, "days_rel": 195, "gap_med": 256.5, "n_releases_24m": 3}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 1084, forks 121 (observed 2026-08-28T04:03:31.424947+00:00)

## What it is
bddisasm is a fast, lightweight x86/x64 instruction decoder library written in C with no external dependencies, no memory allocation, and thread safety. It also includes bdshemu, a basic instruction emulator designed to detect shellcode-like behavior, plus CLI tooling and Python/Rust bindings.

## Use cases
- decode x86/x64 machine code instructions
- disassemble raw binary files from the command line
- emulate shellcode to detect malicious behavior
- integrate disassembly into hypervisors or kernel drivers
- analyze malware samples statically
- add x86 disassembly to Python or Rust tooling

## When to choose
- you need a fast, dependency-free x86/x64 decoder usable in user, kernel, or hypervisor contexts
- you want shellcode behavior emulation without a heavyweight emulator
- you need detailed instruction info like operand access modes, CPUID flags, and flags access

## When to avoid
- you need disassembly for architectures other than x86/x64
- you need full system emulation with API call support
- you want a high-level interactive reverse-engineering suite like a full disassembler GUI

## Facets
- artifact type: library
- maturity: active
- function: parser, reverse-engineering, security, simulation, developer-tools
- domain: security, reverse-engineering, developer-tools, operating-systems
- platform: windows, cross-platform, python, rust, cpp, cli
- tags: x86, x64, disassembler, instruction-decoder, shellcode-emulation, hypervisor, kernel, no-dependencies, thread-safe, linux, macos

## Member repositories
- bitdefender/bddisasm (main) score 74

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:03:31.424947+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-30T06:50:00.708991+00:00, confidence not recorded.
  - readme: https://github.com/bitdefender/bddisasm (fetched 2026-08-28T04:03:31.424947+00:00, sha b138876150c3)
- Data as of 2026-08-30T08:39:29.467469+00:00.