Mach-O

Mach-O Runtime Architecture - http://math-atlas.sourceforge.net/devel/assembly/MachORuntime.pdf
Mach-O Programming Topics - https://developer.apple.com/library/content/documentation/DeveloperTools/Conceptual/MachOTopics/0-Introduction/introduction.html
OS X ABI Mach-O File Format Reference (PDF)
osx-re-101 - https://github.com/michalmalik/osx-re-101
Reverse Engineering/Mac OS X - https://en.wikibooks.org/wiki/Reverse_Engineering/Mac_OS_X

Readings

Basics of the Mach-O file format - https://samhuri.net/posts/2010/01/basics-of-the-mach-o-file-format/
Dynamic Linking: ELF vs. Mach-O - http://timetobleed.com/dynamic-linking-elf-vs-mach-o/
Dynamic Linking of Imported Functions in Mach-O - https://www.apriorit.com/dev-blog/225-dynamic-linking-mach-o / https://www.codeproject.com/Articles/187181/Dynamic-Linking-of-Imported-Functions-in-Mach-O
Dynamic symbol table duel: ELF vs Mach-O, round 2 - http://timetobleed.com/dynamic-symbol-table-duel-elf-vs-mach-o-round-2/
DYLD Detayled - The internals of DYLD, the dynamic linker, and the __LINKEDIT section - http://newosxbook.com/articles/DYLD.html
Extracting libraries from dyld_shared_cache - https://worthdoingbadly.com/dscextract/
Friday Q&A 2012-04-27: PLCrashReporter and Unwinding the Stack With DWARF - https://www.mikeash.com/pyblog/friday-qa-2012-04-27-plcrashreporter-and-unwinding-the-stack-with-dwarf.html
Friday Q&A 2012-05-04: PLCrashReporter and Unwinding the Stack With DWARF, Part 2 - https://www.mikeash.com/pyblog/friday-qa-2012-05-04-plcrashreporter-and-unwinding-the-stack-with-dwarf-part-2.html
Friday Q&A 2012-11-09: dyld: Dynamic Linking On OS X - https://www.mikeash.com/pyblog/friday-qa-2012-11-09-dyld-dynamic-linking-on-os-x.html
Friday Q&A 2012-11-30: Let's Build A Mach-O Executable - https://www.mikeash.com/pyblog/friday-qa-2012-11-30-lets-build-a-mach-o-executable.html
Having Fun with Obfuscated Mach-O Files - https://www.pnfsoftware.com/blog/having-fun-with-obfuscated-mach-o-files/
Hello Mach-O: Dissection of minimal Intel 32-bits, 204 bytes, Mach-O "Hello World" executable file - http://seriot.ch/hello_macho.php
Mach-O Binaries - http://www.m4b.io/reverse/engineering/mach/binaries/2015/03/29/mach-binaries.html
Mach-O Executables - https://www.objc.io/issues/6-build-tools/mach-o-executables/
MacOS Dylib Injection through Mach-O Binary Manipulation
- https://malwareunicorn.org/workshops/macos_dylib_injection.html
Parsing Mach-O files - https://lowlevelbits.org/parsing-mach-o-files/
Playing with Mach-O binaries and dyld
- https://blog.lse.epita.fr/articles/82-playing-with-mach-os-and-dyld.html
- https://lse.epita.fr/data/lt/2017-03-14/lt-2017-03-14-Stanislas_Lejay-Playing_with_machos_and_dyld.pdf
Redirection of Imported Functions in Mach-O - https://www.codeproject.com/Articles/187192/Redirection-of-Imported-Functions-in-Mach-O
Running Executables on macOS From Memory - https://blog.cylance.com/running-executables-on-macos-from-memory
Runtime binary loading via the dynamic loader on Apple Mac OS X - http://www.subreption.com/blog/2009/02/runtime-binary-loading-via-the-dynamic-loader-on-apple-mac-os-x.html
The Mach-O Transition: Darling in the Past 5 Years - http://blog.darlinghq.org/2017/02/the-mach-o-transition-darling-in-past-5.html

Tools/Software

cctools-port: Apple cctools port for Linux, *BSD and Windows (Cygwin)
- https://github.com/tpoechtrager/cctools-port
jtool: (Mach-O Analyzer) - http://www.newosxbook.com/tools/jtool.html
MacDependency: shows all dependent libraries and frameworks of a given executable, dynamic library or framework on Mac OS X
- https://github.com/kwin/macdependency/
mach_override: runtime function overriding for Mac OS X - https://github.com/rentzsch/mach_override
MachoAnalysis: collection of analysis utils - https://github.com/eeeyes/macho_analysis
macholibre: Mach-O & Universal Binary Parser - https://github.com/aaronst/macholibre
- Mach-O Libre: Pile Driving Apple Malware with Static Analysis, Big-Data, and Automation - https://www.first.org/resources/papers/conf2016/FIRST-2016-130.pdf
machO-tools - https://github.com/bx/machO-tools
MachOExplorer - https://github.com/everettjf/MachOExplorer
Machotools - "a small set of tools built on top of macholib to retrieve and change informations about mach-o files. Think of it as a pure python, cross-platform implementation of install_name_tool"
- https://github.com/enthought/machotools
MachOView: a visual Mach-O file browser - https://sourceforge.net/projects/machoview/
MachOView fork: https://github.com/gdbinit/MachOView
Maloader: userland Mach-O loader for Linux - https://github.com/shinh/maloader

Talks

2018 - Mach-O Tricks
- BaiJiuCon at Mobile Security Conference (MOSEC) 2018
- http://iokit.racing/machotricks.pdf
2013 - DEF CON 21 - Mach-O Malware Analysis: Combatting Mac OSX/iOS Malware with Data Visualization
2009 - Black Hat DC - Let your Mach-O fly - Vincenzo Iozzo
- Slides: http://www.blackhat.com/presentations/bh-dc-09/Iozzo/BlackHat-DC-09-Iozzo-Macho-on-the-fly.pdf
- Paper: http://www.blackhat.com/presentations/bh-dc-09/Iozzo/BlackHat-DC-09-Iozzo-let-your-mach0-fly-whitepaper.pdf

Tags: format macos elf dwarf macho

Last modified 07 July 2025

Mach-O

macOS executable file format.

Readings

Tools/Software

Talks