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CHAPTER 6
High-tech investigations of cyber crime
If attendance at a “crime scene” is required then the overarching rule is to pre-
serve the evidence. This, however, cannot come before the safety of those on site.
Once personal safety is assured then evidential preservation can commence. At the
first opportunity everyone not involved in the investigation should be removed from
the vicinity of all keyboards or mice (or other input device) so that no interaction can
be made with any digital device. If left, people can cause untold damage to the digital
data making the later stage of the investigation much harder, if not impossible.
The physical “crime scene” should be recorded using photographs, video record-
ings, and sketches. This makes it possible to identify the location of devices at a later
date, and also allows a third party to see the layout and the devices
in situ
. It may
be that these images are reviewed at a later date and, following analysis, important
points found in the digital data allow inferences to be drawn from what was physi-
cally present; such as the connection of a USB DVD writer.
With the sheer number of digital devices that may be present at a “crime scene”
consideration must be made to the likelihood that a device contains information in re-
lation to the investigation. It is no longer feasible to go on site and seize every single
digital item, budgets and time constraints will not allow this. Consideration must be
made as to the investigation type, the owner of the device and any intelligence and
background information available to determine whether the device is suitable for
seizure. Such a decision should be made in conjunction with the lead investigator and
legal and procedural restrictions.
If a device requires seizing, it should first be determined if the device is on or
off. If on, then consideration should be made of live data capture and a record made
of all visible running programs and processes. Once a decision has been made and
any live data captured, the power should then be removed from the device. If the
device is a server, or similar device, running critical systems and databases, then the
correct shutdown procedure should be followed. It is possible that an unscrupulous
individual has “rigged” a system to run certain programs, or scripts, when it is shut-
down, such as wiping data or modifying certain information; however, the risk of
losing critical business information through a corrupted database or system needs to
be considered fully. Generally a normal home laptop or computer can simply have
the power removed. Once taken offline, or if it is already off, the device should be
placed into an evidence bag with a tamper evidence seal and the chain of custody
maintained. Each device should be given a unique reference number to aid identifica-
tion - and these should be unique to each high-tech investigation.
Once the crime scene is physically secure attention needs to be made of the de-
vices to be seized and how technically to achieve that - this is detailed in the follow-
ing sections.
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