5 Essential Tools to Learn on SIFT Workstation

Quick definition: The SIFT Workstation is a valuable collection of open-source tools used to collect digital evidence on systems after a security incident. These five tools are essential for IT professionals in cybersecurity. 

Digital forensics and incident response (DFIR) is an increasingly essential field in cybersecurity that investigates and collects digital evidence after a security incident. 

One of the most valuable tools in DFIR is the SANS Investigative Forensic Toolkit (SIFT) Workstation, an open-source collection of tools for facilitating digital investigations. In this article, we'll cover five of the top tools from the SIFT Workstation. We will also dig briefly into DFIR, how it improves security resilience, and how you can start implementing it in your organization.

What is DFIR?

DFIR was born out of a need to formally investigate security incidents. The "digital forensics" part involves collecting, analyzing, and preserving evidence such as logs, network traffic, malware artifacts, memory dumps, and logs from security software and appliances. Handling all this data is key to understanding how an incident occurred and preventing future attacks. 

The second part of DFIR, "incident response," refers to having a plan to avoid (or at least minimize) chaos before an incident occurs. This can include identifying key roles and responsibilities, training staff in DFIR techniques, having clear processes and playbooks ready to execute, and using tools like the SIFT Workstation.

Introduction to SIFT Workstation

Speaking of SIFT Workstation, let's pivot to this Swiss army knife of DFIR tooling. SIFT Workstation was assembled by SANS to complement their DFIR training courses, like FOR508: Advanced Incident Response and Threat Hunting. 

In their own words, SIFT "demonstrates that advanced incident response capabilities and deep-dive digital forensic techniques can be accomplished using cutting-edge open-source tools that are freely available and frequently updated."

It can be installed either as a virtual machine appliance (much like Kali Linux) or as a separate download of the entire toolset for Linux or Windows. SANS has a complete set of instructions that walks you through how to install the program. 

Let's explore five of the most powerful tools in SIFT. These are tools you need to know as you delve deeper into the world of DFIR.

1. Plaso

Plaso generates timelines based on the collection and analysis of evidence from sources like system and app logs, registry changes, and browser histories. It can ingest all these sources, parse the data based on the source, and correlate events by time stamps to generate timelines.

During a digital forensic investigation, an analyst can use these timelines to look for insights into the sequence of events of an incident. They might be looking for indicators of compromise, patterns of malicious behavior, or other user interactions with the system.

Plaso can handle very large amounts of logs from many different sources, automating what would otherwise be tedious and time-consuming work. It provides a single source of truth about what happened on any system at a given time.

Plaso also outputs to a common file format that can be used by other tools. This can help with deeper analysis and collaboration when investigating an incident. Together, the team can create a more complete narrative of the incident and piece together what happened.

2. The Sleuth Kit (TSK)

Taking images of disks is an important part of DFIR. To preserve evidence, a snapshot of a disk can be saved from a specific point in time. This maintains the integrity of that file system so it can be investigated without altering or deleting any files.

TSK is a set of command line tools for analyzing disk images and extracting files from those images. An analyst can use this for file system analysis, tracking changes to files, searching files for keywords, creating hashes of files, or recovering deleted or damaged files.

Autopsy is a GUI frontend commonly used with TSK. This makes it much more user-friendly and helps visualize findings and generate reports.

3. Volatility

Volatility is a memory forensics framework used to extract all kinds of information from RAM dumps, like running processes, open files, command line history, credentials, and cryptographic material. These artifacts provide deep insight into what was happening on a system when the memory dump was captured, even for processes that do not log to disk.

Like with disk images and The Sleuth Kit, creating memory dumps is key in preserving evidence from an incident. Memory is especially tricky since it is so transient; key data can be overwritten at a moment's notice. For this reason, preserving and analyzing memory is an essential step in the DFIR process.

4. RegRipper

The Windows Registry is a database used by Windows to store application and system configuration settings, hardware devices, and user settings. As a vast store of information about the system, it can provide valuable insights, but finding useful information is difficult because of its size and complexity.

RegRippers helps by parsing registry files automatically. It can be used to create timelines of registry key changes and reconstruct event sequences like logons, application executions, system changes, and even artifacts that came from malware. RegRipper can automate this tedious analysis, saving valuable time during an investigation.

5. ClamAV

ClamAV is an antivirus engine for detecting and removing malware in real-time or during on-demand scheduled scans. Based on signatures, heuristics, and ML algorithms, it can detect many forms of malware, even undocumented zero-day attacks.

As malware is a common factor in security incidents, ClamAV is an important tool for quickly identifying threats. While an engineer might integrate ClamAV into their security infrastructure, a DFIR analyst can use it to identify malware artifacts and compromised files.

Final Thoughts 

Even in the ever-changing landscape of cybersecurity, bad actors who compromise systems always leave digital footprints behind. Identifying that evidence is key to reconstructing what happened during an incident, and the SIFT Workstation is a valuable collection of these and many other tools that should be in a DFIR analyst's toolkit.

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