In the world of modern cybersecurity, mass storage analysis is a crucial skill. Hard drives, SSDs, USB drives, and mobile devices can contain vital evidence during a cyber investigation. Using digital forensics techniques , specialists can recover deleted data, identify hidden malware, and reconstruct attacker activity.
In this article, we’ll explore the most commonly used techniques, key tools, and best practices for effective analysis.
What is mass storage?
Mass storage devices are devices designed for long-term digital data storage. Among the most common are traditional hard disk drives (HDDs), solid-state drives (SSDs), USB flash drives, memory cards, and even mobile devices such as smartphones and tablets.
During a forensic investigation, it’s crucial to distinguish between live analysis and dead analysis . Live analysis involves working on a system that’s still running to capture volatile data, such as that stored in RAM; dead analysis involves working on an exact copy of the powered-off device, avoiding any alteration of the original data.
Why is mass storage analysis important in cybersecurity?
When a cyber incident occurs, the contents of mass storage devices can tell a detailed story: where the attacker entered, what they did, what data they touched or encrypted. Analysis therefore allows you to identify hidden malware, recover deleted data, reconstruct suspicious activity through logs and timestamps, and ultimately gather evidence that can be used in legal proceedings.
In an age where ransomware and data theft are rife, the ability to extract this information can mean the difference between a business recovering quickly and one suffering irreparable damage.
How Does Mass Storage Analysis Work?
The forensic analysis of a mass storage device follows a very precise methodical sequence.
It begins with the creation of a forensic image of the device, a bit-for-bit copy that guarantees data integrity using hashing algorithms such as MD5 or SHA-256. This copy is then verified to ensure it exactly reflects the original.
The analysis continues by studying the file system structure, specifically elements such as the Master File Table (MFT) in NTFS systems, the Windows registry, and event logs. Equally important is data carving, which allows for the recovery of deleted file fragments without relying on the file system structure.
Finally, the so-called forensic artifacts are analyzed: temporary files, shortcuts (.lnk), browsing histories, paging files and anything else that can provide clues about the activities carried out on the device.
The main tools for analysis
Numerous tools support forensic analysts in their work. Autopsy, for example, is a widely used open-source platform for analyzing disks and file systems. FTK Imager is an application specialized in creating forensic images, while EnCase Forensic proves essential for more complex investigations thanks to its wide range of features.
For mobile and cloud analytics, Magnet AXIOM is an excellent choice. Additionally, it’s not uncommon for more experienced professionals to develop custom scripts in Python or Bash to automate repetitive tasks or analyze large volumes of data.
Practical cases of forensic analysis
The concrete application of these techniques can vary greatly.
In a ransomware attack, for example, mass storage analysis allows for the identification of the malware’s initial entry point, understanding how it propagated, identifying encrypted files, and gathering evidence of the attacker’s activities.
In insider threat scenarios, however, analysis can lead to the recovery of files copied to USB devices, the reconstruction of manipulated system histories, or the discovery of previously hidden suspicious activity.
Best practices for correct analysis
To ensure the legal and technical validity of the evidence collected, it is essential to adhere to certain best practices.
These include preserving the chain of custody by recording every stage of the analysis, working exclusively with forensic copies of the original device, meticulously documenting all operations performed, and adopting recognized international standards, such as those defined by the ISO/IEC 27037 standard.
Conclusions
Mass storage analysis is a complex discipline that requires rigor, technical expertise, and attention to detail. But it is also one of the most powerful tools available to cybersecurity professionals, enabling them to effectively respond to incidents, prevent future threats, and obtain legal redress.
Investing in forensic expertise and the right tools is no longer optional: it is a strategic necessity for any organization that wants to defend itself in today’s digital world.
