Finding Call Reference Hooks in Mac Memory

In this blog post the call reference to the function _vnode_pagein in the function _ps_read_file will be modified to show a call reference modification and  and a Volatility Framework plugin to detect this type of hooking will be presented.

Detecting Shadow TrustedBSD Policy Tables In Mac Memory

In this blog post the reference of the _mac_policy_list in _mac_proc_check_get_task will be modified to reference the 'shadow' TrustedBSD policy table and a Volatility Framework plugin to detect this type of hooking will be presented.

Back to Defense: Finding Hooks in OS X with Volatility

Summary

In my previous post I discussed how to mess with the OS X syscall table through direct syscall table modification, syscall function inlining, and patching the syscall handler. As I promised, I'll be providing a plugin to find the mess! The code for the check_hooks plugin can be found at github and it incorporates existing detections for the sake of completeness. So let's go through the scenarios discussed earlier.

Offensive Volatility: Messing with the OS X Syscall Table

Summary

After taking a brief detour into reviewing JAVA source code I'm back to OS X and Volatility. In this post I'll be using the Volatility Framework to alter the OS X syscall table from an offensive perspective rather than using it for detection. To accomplish this, I'll be mimicking techniques used by malware, such as direct syscall table modification, syscall function inlining, patching the syscall handler, and hiding the payload in a binary's segment.