Authors: Vincent van der Meer (Zuyd University of Applied Science), Hugo Jonker (Open University of the Netherlands), and Jeroen van den Bos (Netherlands Forensic Institute)
DFRWS APAC 2021
Abstract
There is a significant amount of research in digital forensics into analyzing file fragments or reconstructing fragmented data. At the same time, there are no recent measurements of fragmentation on current, in-use computer systems. To close this gap, we have analyzed file fragmentation from a corpus of 220 privately owned Windows laptops.
We provide a detailed report of our findings. This includes contemporary fragmentation rates for a wide variety of image-, video-, office-, database-, and archive-related extensions. Our data substantiates the earlier finding that fragments for a significant portion of fragmented files are stored out-of-order. We define metrics to measure the degree of “out-of-orderedness” and find that the average degree of out-of-orderedness is non-negligible. Finally, we find that there is a significant group of fragmented files for which reconstruction is insufficiently addressed by current tooling.