---
id: 1925
title: "Rewriting Functions in Compiled Binaries"
source_domain: blog.trailofbits.com
source_url: "https://blog.trailofbits.com/2019/09/02/rewriting-functions-in-compiled-binaries/"
published_at: "2019-09-02T10:50:31Z"
tags: ["cryptography", "reverse-engineering", "binary-analysis", "llvm", "mcsema", "binary-rewriting", "function-replacement"]
phying_url: "https://phying.com/item/1925"
lang: en
---

# Rewriting Functions in Compiled Binaries

## Summary

An intern built Fennec, a McSema-based tool that lifts compiled binaries to LLVM IR and rewrites function calls automatically—demonstrated by swapping crypto routines inside stripped binaries.

## Intelligence Metadata

- **Sources:** blog.trailofbits.com
- **Published:** 2019-09-02T10:50:31Z
- **Original:** https://blog.trailofbits.com/2019/09/02/rewriting-functions-in-compiled-binaries/
- **Phying News:** https://phying.com/item/1925