Tag: Malware Analysis

Portable Executable File Corruption Preventing Malware From Running

Important Disclaimer – YOU MUST READ FIRST! Portions of this article contain source code from the Windows Research Kernel. This code is the intellectual property of Microsoft Corporation. I am using this code under special license in this post under these grounds of the license agreement: You may distribute snippets of this software in research…


Windows Special Folders: CSIDLs, KNOWNFOLDERID

Introduction As we’ve seen many times before, malware authors are always trying to get at important system folders on victim systems. Some reasons for this are: To locate and attack actual operating system files To impersonate or spoof system files or create files with similar names in an attempt to circumvent detection. For example –…


EquationGroup DoubleFantasy Part 1

Introduction EquationGroup has a malware called DoubleFantasy. Sounded interesting, so I decided to go ahead and attack it and find out what it’s all about. Supposedly Kaspersky said about EquationGroup, The Equation Group is probably one of the most sophisticated cyber attack groups in the world; and they are the most advanced threat actor we…


What is a Malware Analyst and Why will your organization need one very soon?

Introduction I predict within the next 5-10 years, the number of malware analyst, researcher, and reverse-engineer jobs is going to skyrocket. So what is a malware analyst, malware researcher, and/or malware reverse-engineer in the first place and why will they be in high demand? What is a Malware Analyst/Researcher/Reverse Engineer? First of all, the slashes…


Hiding from disassembly analysis

There are several patterns that I’ve picked up on in which malware authors try to hide function calls, a large one being by using other function calls. To analysts who are experienced with the operating system’s API and system calls, this is not a big deal, but to those who are not, they are effective…


PortEx Analyzer

I wanted to mention a tool that I’ve found very helpful in analyzing Portable Executable (PE) files: PortEx Analyzer by Karsten Hahn. Actually, the first very noticeable difference between this program and so many others is the level of documentation. PortEx Analyzer is fully documented by Hahn and has a thorough readme and wiki as…


Inline Hook of a System Call via AppInit_DLLs Part 2– The Hook

For an introduction, please refer to Part 1 of this analysis. The Installer Still inside the same Lab11-02.dll as before, we can return back to DllMain and locate one more subroutine call, which takes us to the hook code, but this is incomplete knowledge since we haven’t yet seen how the hook even gets installed…


Inline Hook of a System Call via AppInit_DLLs Part 1 – Decryption of XOR Cipher

  Introduction This will be a 2 part post. In part 1 I will demonstrate deciphering a simple XOR encryption used in Lab 11-02 of Practical Malware Analysis by Sikowski. This lab also demonstrates a technique called inline hooking, where malware installs itself onto the system as a code library file (DLL) and then redirects…


Entry-Point Redirection used in a keylogger

Introduction As I mentioned in a previous post, to expand my knowledge, I am working through the labs in the book Practical Malware Analysis by Michael Sikorski. In this post, I will demonstrate my findings in Lab 11-03, which illustrate entry-point redirection. Why would malware even want to use entry point redirection in the first…


Several methods malware can hide itself on Windows

Introduction Back in the day of Windows 95, 98, and (ugh) ME, I vividly remember getting malware on my machine a handful of times. Each time usually involved the computer slowing down to a crawl, strange popup and error messages about files coming up which were usually DLLs, and just all around obvious and suspicious…