Bog'liq Cyber crime and cyber terrorism investigators handbook by Babak
1. Pre-Analysis : if this is done incorrectly it can have a major impact on the
rest of the investigation. It is the process of getting the data ready to make the
actual analysis as smooth as possible. This process is all about preparing the
data through the recovery of deleted files and partitions, and the mounting of
compressed file and folders and encrypted files (so they then become searchable
and have context)
2. Analysis : this is the review of the data to find information that will assist in the
investigation, through the identification of evidence that proves, or disproves, a point
A high-tech investigation should not be dependent upon the tool used; a tool is simply
a means to an end. However, it is important that the investigator is comfortable and suf-
ficiently qualified and experienced in using the chosen digital analysis tool. The ability
to click a button in a forensic tool or to follow a predefined process is not forensics—
this is evidential data recovery. A high-tech investigator must be able to review what
is in front of them and interpret that information to form a conclusion, and if appropri-
ate, an opinion. The location of evidence can be as important as the evidence itself;
therefore careful consideration must be made as to the context of what is seen. If a file
resides in a user’s personal documents folder, it does not mean that they put it there. It
is the investigator’s role to identify its provenance and provide context as to how it got
there, when, and whether it has been opened. The interpretation and production of such
information may help in proving, or disproving, an avenue of investigation.
There is no correct way to begin the actual analysis of the data; there is no rule
book which will state exactly what to do and what to look at. Depending on any legal
restrictions, the investigator may be limited to only reviewing certain files and data.
If there is any uncertainty on this issue the investigator must discuss this with their
manager or the senior investigator. If all data can be accessed then the investigator
can browse through the folders and files. If anything stands out as “unusual” or of
interest it may provide direction and focus to the technical analysis steps. To some
extent this may depend on the operating system under review.
At the start of an investigation a check should be made to ensure that all the
expected data in the capture is accounted for. It is very easy for partitions on a disc
to be modified so that they are not seen straight away or for a partition to be deleted
and a new one created. In terms of a physical disc this may involve the review of the
number of sectors available on the disc compared to those currently used.