Digital devices are ubiquitous and their use in chain-of-evidence investigations is crucial. Today’s smoking gun is more likely to be a laptop or a phone than it is a more literal weapon. Whether such a device belongs to a suspect or victim, the vast swathes of data these systems contain could be all an investigator needs to put together a case.
That said, retrieving that data in a secure, efficient, and lawful manner is not always a simple endeavor. Investigators are increasingly relying upon new digital forensics tools to assist them.
Digital forensics tools are all relatively new. Up until the early 1990s, most digital investigations were conducted through live analysis, which meant examining digital media by using the device-in-question as anyone else would. As devices became more complex and packed with more information, live analysis became cumbersome and inefficient. Eventually, freeware and proprietary specialist technologies began to crop up as both hardware and software to carefully sift, extract, or observe data on a device without damaging or modifying it.
Digital forensics tools can fall into many different categories, some of which include database forensics, disk and data capture, email analysis, file analysis, file viewers, internet analysis, mobile device analysis, network forensics, and registry analysis. Many tools fulfill more than one function simultaneously, and a significant trend in digital forensics tools are “wrappers”—one that packages hundreds of specific technologies with different functionalities into one overarching toolkit.
New tools are developed every day, both as elite government-sponsored solutions and basement hacker rigs. The recipe for each is a little bit different. Some of these go beyond simple searches for files or images, and delve into the arena of cybersecurity, requiring network analysis or cyber threat assessment. When there is a tool for everything, the most pressing question is which one to use.
Below, ForensicsColleges has collected some of the best tools for digital forensics and cybersecurity. In selecting from the wide range of options, we considered the following criteria:
Autopsy is a digital forensics platform and graphical interface that forensic investigators use to understand what happened on a phone or computer. It aims to be an end-to-end, modular solution that is intuitive out of the box. Select modules in Autopsy can do timeline analysis, hash filtering, and keyword search. They can extract web artifacts, recover deleted files from unallocated space, and find indicators of compromise. All of this can be done relatively rapidly.
Autopsy runs background jobs in parallel so that even if a full search takes hours, a user will know within minutes whether targeted keywords have been found. Investigators working with multiple devices can create a central repository through Autopsy that will flag phone numbers, email addresses, or other relevant data points.
Developed by the same team that created The Sleuth Kit, a library of command line tools for investigating disk images, Autopsy is an open source solution, available for free in the interests of education and transparency. The latest version is written in Java, and it is currently only available for Windows.
CAINE offers a full-scale forensic investigation platform designed to incorporate other tools and modules into a user-friendly graphic interface. Its interoperable environment is designed to assist investigators in all four stages of an investigation: preservation, collection, examination, and analysis. It comes with dozens of pre-packaged modules (Autopsy, listed above, is among them). Developed on Linux, the tool is entirely open source and available for free.
Digital Forensics Framework (DFF) is an open source computer forensics platform built upon a dedicated Application Programming Interface (API). Equipped with a graphical user interface for simple use and automation, DFF guides a user through the critical steps of a digital investigation and can be used by both professionals and amateurs alike.
The tool can be used to investigate hard drives and volatile memory and create reports about system and user activity on the device in question. The DFF was developed with the three main goals of modularity (allowing for changes to the software by developers), scriptability (allowing for automation), and genericity (keeping the operating-system agnostic to help as many users as possible). The software is available for free on GitHub.
The Volatility Foundation is a nonprofit organization whose mission is to promote the use of memory analysis within the forensics community. Its primary software is an open source framework for incident response and malware detection through volatile memory (RAM) forensics. This allows the preservation of evidence in memory that would otherwise be lost during a system shutdown.
Written in Python and supportive of almost all 32-bit and 64-bit machines, it can sift through cached sectors, crash dumps, DLLs, network connections, ports, process lists, and registry files. The tool is available for free, and the code is hosted on the Google Code Archive.
Initially a product of Mandiant, but later taken over by FireEye, a cybersecurity firm, Redline is a freeware tool that provides endpoint security and investigative capabilities to its users. It is mainly used to perform memory analysis and look for signs of infection or malicious activity, but it can also be used to collect and correlate data around event logs, the registry, running processes, file system metadata, web history, and network activity.
Offering much more technical and under-the-hood capability than most digital forensics investigations necessitate, Redline has more applications in cybersecurity and other tech-driven criminal behavior where a granular analysis is critical. Redline currently only functions on Windows-based systems, but it is regularly updated by FireEye for optimum performance and can be downloaded for free on the FireEye website.
Microsoft’s Computer Online Forensic Evidence Extractor (COFEE) is a forensic toolkit used to extract evidence from Windows computers. Developed in 2006 by a former Hong Kong police officer turned Microsoft executive, the toolkit acts as an automated forensic tool during a live analysis. It contains more than 150 features and a graphical user interface that guides an investigator through data collection and examination and helps generate reports after extraction. Password decryption, internet history recovery, and other forms of data collection are all included in the toolkit.
At the time of its release, Microsoft claimed that COFEE had reduced three- to four-hour tasks to under 20 minutes. Thousands of law enforcement agencies across the world (including INTERPOL) use COFEE and Microsoft provides them with free technical support.
In November 2009, COFEE was leaked onto multiple torrent sites, and while it is possible—though incredibly tricky—for criminals to build around the features in COFEE, it is also possible for the average citizen to now get a look at what was once the industry standard across the world for digital forensics.
Wireshark is the world’s most-used network protocol analysis tool, implemented by governments, private corporations, and academic institutions across the world. As the continuation of a project that began in 1998, Wireshark lets a user see what is happening on a network at the microscopic level. By capturing network traffic, users can then scan for malicious activity.
Captured network data can be viewed on a graphical user interface on Windows, Linux, OSx, and several other operating systems. The data can be read from Ethernet Bluetooth, USB, and several others, while the output can be exported to XML, PostScript, CSV, or plain text.
Wireshark’s applications remain primarily in cybersecurity, but there are digital forensics investigation applications as well. Less about the smoking gun than the breadcrumb trail, Wireshark can point an investigator in the direction of malicious activity so that it can be tracked down and investigated.
DumpZilla performs browser analysis, specifically of Firefox, Iceweasel, and Seamonkey clients. It allows for the visualization and customized search and extraction of cookies, downloads, history, bookmarks, cache, add-ons, saved passwords, and session data.
Developed in Python, it works under Linux and Windows 32/64 bit systems, and DumpZilla is available for free from the developer’s website. While this was created as a standalone tool, its specific nature and lean packaging make it a strong component of future digital forensics suites.
The SANS Investigative Forensics Toolkit (SIFT) is a collection of open source incident response and forensics technologies designed to perform detailed digital investigations in a variety of settings. The toolkit can securely examine raw disks and multiple file formats and does so in a secure, read-only manner that does not alter the evidence it discovers.
SIFT is flexible and compatible with expert witness format (E01), advanced forensic format (AFF), and raw evidence formats. Built on Ubuntu, it incorporates many separate tools (including some on this list, such as Autopsy and Volatility) and puts them at an investigator’s disposal. SIFT is available for free and updated regularly.
ExifTool is a platform-independent system for reading, writing, and editing metadata across a wide range of file types. Of particular interest to the digital investigator is the reading of metadata, which can be achieved through command-line processes or a simple GUI. Investigators can drag and drop different files, such as a PDF, or a JPEG, and learn when and where the file was created—a crucial component in establishing a chain of evidence.
The software itself is lightweight and quick, making it an ideal inclusion in future digital forensics suites, and easy to use. ExifTool is available for both Windows and OSx and is available from the developer’s website.
Bulk Extractor scans a file, directory, or disk image and extracts information without parsing the file system or file system structures, allowing it to access different parts of the disk in parallel, making it faster than the average tool. The second advantage of Bulk Extractor is that it can be used to process practically any form of digital media: hard drives, camera cards, smartphones, SSDs, and optical drives. The most recent versions of Bulk Extractor can perform social network forensics as well.
All extracted information can be processed either manually or with one of four automated tools, one of which incorporate context-specific stop lists (i.e., search terms flagged by the investigator) that remove some of the human error from digital forensics investigation. The software is available for free for Windows and Linux systems.
Matt Zbrog is a writer and freelancer who has been living abroad since 2016. His nonfiction has been published by Euromaidan Press, Cirrus Gallery, and Our Thursday. Both his writing and his experience abroad are shaped by seeking out alternative lifestyles and counterculture movements, especially in developing nations. You can follow his travels through Eastern Europe and Central Asia on Instagram at @weirdviewmirror. He’s recently finished his second novel, and is in no hurry to publish it.