Analyzing Malware to Identify Threats

Tutorial 4 of 5

Introduction

This tutorial is designed to introduce you to malware analysis, an essential skill for cybersecurity professionals. By the end of this tutorial, you will be familiar with basic malware analysis techniques. You will be capable of identifying and understanding the functionality, origin, and potential impact of a given piece of malicious software.

Prerequisites: Basic knowledge of programming and understanding of operating systems is useful. Familiarity with any scripting language and hexadecimal is a plus, but not essential.

Step-by-Step Guide

1. Setting Up the Environment

Before analyzing malware, we need to set up a safe and isolated environment. We usually use virtual machines for this purpose. Tools like VirtualBox or VMware are suitable.

Tip: Always disconnect your virtual machine from the network when analyzing malware to prevent accidental leaks.

2. Static Analysis

Static analysis involves examining the malware without executing it. Tools such as strings, PEiD, and IDA Pro can be used for static analysis.

Example:
To analyze strings (readable characters) within the malware, we use the strings command in Linux:

strings malware_file

The output will display all the strings present in the file, which might provide useful information about what the malware does.

3. Dynamic Analysis

Dynamic analysis involves running the malware and observing its behavior. Tools like Wireshark, Process Monitor, and Regshot are used for dynamic analysis.

Example:
To monitor network traffic while the malware is running, we use Wireshark:

wireshark &
./malware_file

This will show all the network packets sent/received while the malware is running.

Code Examples

1. Static Analysis

Let's use PEiD to identify the packer used by the malware.

peid malware_file

The output will show the packer used, which gives us insights into the methods used by the malware to avoid detection.

2. Dynamic Analysis

We'll use Process Monitor to observe file system activity.

procmon -f malware_file

The output will show all the system calls made by the malware, revealing its behavior.

Summary

In this tutorial, we've covered basic malware analysis techniques including setting up a safe analysis environment, static analysis, and dynamic analysis. To further your learning, practice analyzing different types of malware and using different tools for analysis.

Practice Exercises

1. Beginner: Set up a safe environment and perform static analysis on a malware sample using the strings command.

2. Intermediate: Perform dynamic analysis on a malware sample. Monitor its network activity using Wireshark.

3. Advanced: Perform both static and dynamic analysis on a malware sample. Try to identify its functionality, origin, and potential impact.

Solutions

  1. Set up a VirtualBox, disconnect from the network, and use strings malware_file to analyze strings.

  2. In the same environment, run wireshark & and ./malware_file to capture network packets.

  3. Use all the above techniques plus PEiD and Procmon tools to analyze the malware. Research the strings, IP addresses, and system calls you come across.

Please remember, practice is key to mastering malware analysis. Happy learning!