Practical Malware Analysis: A Hands-On Approach

Introduction

Malware analysis is a critical skill in cybersecurity, allowing professionals to understand how malicious software operates, identify indicators of compromise (IoCs), and develop effective defense strategies. This article provides a practical approach to malware analysis, based on techniques from Sikorski and Honig’s Practical Malware Analysis (No Starch Press, 2012).


Types of Malware Analysis

1. Static Analysis (Without Execution)

Static analysis involves examining a malware sample without running it. This method is useful for quickly identifying basic indicators of compromise (IoCs), such as:

  • File metadata (size, hash values)
  • Strings analysis (extracting readable text for potential clues)
  • Portable Executable (PE) headers
  • Embedded resources (icons, images, configurations)

Tools for Static Analysis:

  • strings (Extracts readable text from binaries)
  • PEview (Examines PE file headers)
  • VirusTotal (Scans the hash against known malware databases)

2. Dynamic Analysis (Executing Malware in a Controlled Environment)

Dynamic analysis involves running the malware in a controlled, sandboxed environment to observe its behavior. This helps analysts detect:

  • Network communication (e.g., Command & Control (C2) servers)
  • File modifications (e.g., ransomware encrypting files)
  • Registry changes (e.g., persistence mechanisms)
  • Tools for Dynamic Analysis:
  • Remnux (Linux-based malware analysis toolkit)
  • Procmon (Monitors system calls and process activity)
  • Wireshark (Captures and analyzes network traffic)

Step-by-Step Malware Analysis Process

Step 1: Identify and Hash the File

Before executing any malware, create a hash to track its signature.

bash

Copy code

sha256sum malware_sample.exe

Compare the hash against databases like VirusTotal to see if it has been previously identified.

Step 2: Extract Strings and Metadata

Extract embedded strings that might reveal domains, file paths, or hidden commands.

bash

Copy code

strings malware_sample.exe | more

Use PEview to inspect PE headers, imports, and sections for anomalies.

Step 3: Analyze Malware Behavior in a Sandbox

Run the malware in an isolated virtual machine (VM) or sandbox environment like Cuckoo Sandbox to observe:

  • Network activity (Wireshark)
  • Process activity (Procmon)
  • File modifications (Regshot)

Step 4: Reverse Engineering with Disassembly

If the malware is obfuscated, use IDA Pro or Ghidra to reverse engineer its logic. This can help identify decryption routines, exploits, and backdoor mechanisms.

Leave a Comment

Your email address will not be published. Required fields are marked *