WinPmem is developed as part of the AFF4 imager project. AFF4 is an advanced, open forensic imaging format. The format has been standardized in the AFF4 Standard Specification, and it is increasing more supported by other tools.
WinPmem by default will use AFF4 to store the memory image, but it is also possible to write the image in RAW format or ELF format. You might want to do this if you are going to use the image with tools that can not read AFF4 natively. However, note that using these imaging format will cause WinPmem to skip acquisition of multiple files and metadata making the image harder to use.
Why use AFF4?
The AFF4 format is specifically designed to support a wide range of use cases in forensic evidence capture and preservation. Some of the benefits of using AFF4 over another proprietary format are
The AFF4 format is an opened standard with many open source implementations in a variery of languages. The format itself is very simple and so it will always be possible to extract data even without an proper implementation.
AFF4 storage is designed around the widely used Zip file format. This means that you can use typical Zip recovery utilities to repair corrupted images, inspect the content of images etc.
AFF4 supports multiple streams within the same volume. This allows multiple sources of evidence to be captured into the same case file. For example, related memory, disk and logical file streams can be handled simultaneously. WinPmem uses this property to store memory images in the same volume as important files like drivers and kernel image, thus assisting the analysis phase.
AFF4 supports sparse streams (using the Map stream type). This is useful for representing memory images (which might have gaps in them) as well as simply representing read errors (rather than simply zero padding them).
AFF4 supports arbitrary metadata as RDF statements.
The Pmem memory acquisition suite includes the WinPmem, OSXPmem and LinPmem tool. Each tool implements memory acquisition for its respective OS but all use largely the same options. All the below commands should also work on any tools in the pmem suite. For simplicity we demonstrate with WinPmem.
You can download_ the latest release of the aff4 imager through the project’s release page. Releases are statically built for their respective platforms in order to ensure that they can be easily deployed with minimal system requirements - even on very old systems. You do not need to include any runtime dependencies (like Visual C runtimes).
The following section describes how to use the imager effectively. You can get some helpful messages from the imager itself when run with the –help flag.