Vladimir
A. Golubev
PhD in Law, Associate Professor,
Computer Crime Problems Research Center
Initial investigating actions related to detecting cyber crimes
Like other similar revolutionary technologies,
Internet brings huge potential as for progress as for abuses, attacks in the
net, fraud, software pirates, industrial espionage, children pornography trade
-they are only some crimes committed in the global net.
Initial investigating actions related to detecting
transnational computer crimes (cyber crimes), cause special difficulties, that
is connected with many problems.
The results and analysis of conducted researches of
law-enforcement organs practical activity concerning investigating computer
crimes testify that computer equipment study SHOULD to be carried out in
criminalistical laboratory conditions, when professionals with necessary
training will do this work.
Let us consider some typical mistakes that are often made while carrying
out inquiry actions related to computer information and computers themselves.
Several rules of
working with
computers, expropriated when investigating crimes in computer information
sphere, can be distinguished, we also can propose general recommendations which
may be useful when processing computer evidence in DOS or Windows operational
systems.
Error #1. Erroneous work with a computer.
First and general rule that to be mandatory implemented is: never and
under any conditions not to work on the seized computer. This rule considers a
seized computer as an object for professionals' studying. That is why one
should not even turn it on until transferring to experts, as it is absolutely
prohibited to run any programs on such a computer without using necessary
safety measures (e.g. protection from modification or creating backup files).
If computer has a protection on run up system (e.g. -password), then turning
the computer on can cause destroying the information on hard disk. Turning such
computer on, using its own operational system is not allowed.
This is explained simple enough: a criminal has no difficulty in
installing a program for wiping the information off on hard or floppy disk,
recording such "traps" by operational system modification. For example,
simple DIR command used for displaying disk's catalogue can be changed to
format hard disk.
Then the data and the destroying program itself are deleted nobody can
tell for sure whether the "suspected" computer was specially equipped
with these programs or this was a result of negligence in handling computer
evidence.
Error #2. Letting access of computer owner or user to computer .
Admitting an owner of computer that is being
studied for helping in its work is a serious mistake. Many foreign sources describe
cases when suspected on a questioning, concerning computer evidence was
granted an access to seized computer. Later on they told their friends as they
coded files in the policemen's presence and policemen did not even suspect
anything. Considering these
consequences, quite
quickly computer specialists started to create back up files of computer
information before granting access to it.
Error #3. Absence of computer scanning for viruses and macro-viruses.
To scan a computer for viruses and macro-viruses, it is necessary to
load a computer not from operational system in it, but from prepared in advance
floppy disk, or from experts' hard disk. All information carriers - floppy
disk, hard disk, some others are subjected to check up. Specialist attracted to
inquiry actions using special software should do this work.
It is necessary not to allow the court to accuse the investigator: in
special viruses infection of a computer, or in incompetence when carrying out
inquiry actions or just in negligence, because it is hardly possible to prove
that the virus existed in the computer before its examining, such an accusation
will doubt the expert's work and probability his conclusions. These are the
most typical errors when examining computer in investigating computer crimes.
But described list does not include all mistakes that are possible in the
process of extracting and studying computer in-formation. This is easily
explained: lack of experience in investigating similar cases in our country. At
the same time Western Europe countries, the USA especially, has rich experience
in investigating complicated computer crimes. This experience should be more
thoroughly studied to avoid many mistakes.
To prevent errors in carrying out the inquiry actions at the first investigation
stage which can cause losing or destroying computer information one should keep
to some preventive measures as:
Recommendation 1: First, one should make a reserve copy of information.
When searching and seized computer, magnet
carriers (hard disk, floppy disk), and information there are some common
problems connected
with specific character of seized technical means. It is necessary to foresee
safety measures, which criminal takes to destroy computer information. For
example, he can use special equipment, which under special conditions create
strong magnetic field and thus delete magnet records.
During the search all electronic evidence in computer or computer system
should be collected so that later the court would admit them. World practice
testifies that in many cases under the pressure of defense lawyers in court
electronic evidence are not taken into account. To guarantee their recognition
as evidence, one should strictly keep to criminal-procedural legislation
requirements standard methods of extracting them.
As a rule, computer evidence is kept creating an exact copy from
original (primary evidence) before somehow analyzing it. But it is not enough
to make computer files copies using only standard programs of reserve copying.
Physical evidence can exist as deleted or hidden files, and data, connected
with these files, can be saved only with the help of special software, they can
be Safe Back type programs, for floppy disks DOS Disk copy may be enough.
Magnetic carries which are intended for copying the information should
be prepared in advance (you should be sure they do not contain any
information). Carriers should be kept in special wrapping or wrapped in clean
paper. You should remember that information could be completely spoilt by
humidity, temperature or electrostatic (magnetic) fields.
Recommendation 2. Find and copy temporary files.
Many text editors and databases software create
temporary files as software normal work by-product. Most computer users do not
realize the importance of creating such files, as the program in the end of
work usually deletes them. But the data inside these deleted files may be most
useful. Files could be recovered especially if an output file was coded or a
document was typed.
Recommendation 3. Check Swap File.
Microsoft Windows popularity brought some additional means for studying
computer information. Swap File works as disk memory or huge database, many
different temporary information pieces or even all the document text may be
found in this Swap File.
Recommendation 4. Compare duplicates of text documents.
Duplicates of text files may often be found on hard disk or floppy disk.
These may be slightly changed version of one document that may have value as
evidence. These divergences can be easily identified with the help of modern
text editors.
Recommendation 5. Check and analyze computer network.
Computers may be linked with each at other in computer network (e.g.
local network), that in its turn may be linked to global computer networks
(e.g. Internet). That is why there is possible that certain information (which
can be used as evidence) can be transferred through the net to another place.
This place can be situated abroad or on the territory of several countries.