Category Archives: assembly

Shellcode: Data Compression

Introduction This post examines data compression algorithms suitable for position-independent codes and assumes you’re already familiar with the concept and purpose of data compression. For those of you curious to know more about the science, or information theory, read Data … Continue reading

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Windows Process Injection: Asynchronous Procedure Call (APC)

Introduction An early example of APC injection can be found in a 2005 paper by the late Barnaby Jack called Remote Windows Kernel Exploitation – Step into the Ring 0. Until now, these posts have focused on relatively new, lesser-known … Continue reading

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Windows Process Injection: DNS Client API

Introduction This is a quick response to Code Execution via surgical callback overwrites by Adam. He suggests overwriting DNS memory functions to facilitate process injection. This post will demonstrate how the injection works with explorer.exe. It was only tested on … Continue reading

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Shellcode: In-Memory Execution of JavaScript, VBScript, JScript and XSL

Introduction UPDATE: After being available for twenty years, Dr.Dobb’s removed access to two articles linked from here. I’ve no idea why. A DynaCall() Function for Win32 was published in the August 1998 edition of Dr.Dobbs Journal. The author, Ton Plooy, … Continue reading

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Shellcode: In-Memory Execution of DLL

Introduction In March 2002, the infamous group 29A published their sixth e-zine. One of the articles titled In-Memory PE EXE Execution by Z0MBiE demonstrated how to manually load and run a Portable Executable entirely from memory. The InMem client provided … Continue reading

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Windows Process Injection : Windows Notification Facility

Introduction At Blackhat 2018, Alex Ionescu and Gabrielle Viala presented Windows Notification Facility: Peeling the Onion of the Most Undocumented Kernel Attack Surface Yet. It’s an exceptional well-researched presentation that I recommend you watch first before reading this post. In … Continue reading

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How Red Teams Bypass AMSI and WLDP for .NET Dynamic Code

Introduction Previous Research AMSI Example in C AMSI Context AMSI Initialization AMSI Scanning CLR Implementation of AMSI AMSI Bypass A (Patching Data) AMSI Bypass B (Patching Code 1) AMSI Bypass C (Patching Code 2) WLDP Example in C WLDP Bypass … Continue reading

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