# GJDuck/e9patch

A powerful static binary rewriting tool

Repository: https://github.com/GJDuck/e9patch
Canonical: https://ross.abutalabs.com/products/e9patch
Language: C
License: GPL-3.0
License Family: copyleft
Topics: binary-rewriting, binary-patching, binary-instrumentation, reverse-engineering, binary-analysis, elf, e9patch, binary
Last push: 2026-06-28T02:52:44+00:00

## Health v2 (maintenance only)
Score: 83/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 89, release rhythm 65, longevity 100
- inputs: {"age_days": 2350, "days_push": 66, "days_rel": 72, "gap_med": 112, "n_releases_24m": 2}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 1137, forks 70 (observed 2026-08-28T04:03:43.842216+00:00)

## What it is
E9Patch is a static binary rewriting tool for x86_64 Linux ELF executables and shared objects, producing patched binaries that work as drop-in replacements. It includes E9Tool, a linear disassembly frontend for applying instrumentation like instruction tracing.

## Use cases
- patch a compiled binary without source code
- instrument instructions in an ELF binary for tracing
- insert AFL fuzzing instrumentation into a stripped binary
- harden or modify a large binary like a web browser
- intercept syscalls by rewriting libc

## When to choose
- you need to modify or instrument a Linux x86_64 ELF binary without recompiling
- you need low-overhead, scalable rewriting of very large binaries
- you want a drop-in patched binary with no extra runtime dependencies

## When to avoid
- you need dynamic (runtime) instrumentation rather than static rewriting
- your target is not a Linux x86_64 ELF binary
- you need source-level modification and can rebuild from source

## Facets
- artifact type: cli-tool
- maturity: active
- function: reverse-engineering, security, developer-tools
- domain: security, reverse-engineering, developer-tools, operating-systems
- platform: cli, cpp
- tags: binary-rewriting, binary-patching, binary-instrumentation, elf, x86-64, disassembly, fuzzing-support, linux

## Member repositories
- GJDuck/e9patch (main) score 83

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:03:43.842216+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 2026-08-30T06:36:13.633064+00:00, confidence not recorded.
  - readme: https://github.com/GJDuck/e9patch (fetched 2026-08-28T04:03:43.842216+00:00, sha 23a006cef723)
- Data as of 2026-08-30T08:39:29.467469+00:00.