Harald
Bosch, VIS - Universität Stuttgart, Harald.Bosch@vis.uni-stuttgart.de
Julian Heinrich, VISUS - Uni Stuttgart, Julian.Heinrich@vis.uni-stuttgart.de
Christoph Mueller, VISUS - Uni Stuttgart, Christoph.Mueller@vis.uni-stuttgart.de
Guido Reina, VISUS - Uni Stuttgart, Guido.Reina@vis.uni-stuttgart.de
Michael Wörner, GSaME- Univeristät Stuttgart, Michael.woerner@gsame.uni-stuttgart.de
Steffen Koch,VIS - Universität Stuttgart, Steffen.Koch@vis.uni-stuttgart.de
Benjamin Höferlin, VIS - Universität Stuttgart, Benjamin.Hoeferlin@vis.uni-stuttgart.de
Markus Höferlin, VISUS - Universität Stuttgart, Markus.Hoeferlin@vis.uni-stuttgart.de
The preprocessing of the video was done by a tool developed for this
challenge in Matlab. It analysis the moving objects of the video using a
combined approach of optical flow computation and background subtraction. The
video visualization and user interaction tool were developed for this challenge
is written in C++ and based on OpenGL. The visualization applies the
VideoPerpetuoGram methodology to get a summarization of the actions in the
video. We implemented a real-time filter framework
For the social network analysis, we used customized tools based on
available developments of our department, which were adapted to fit the
challenge’s needs.As development tools we used mainly the Java SDK, Apache
libraries, and the prefuse visualization toolkit. Additionally, Microsoft Excel
was used for some tasks.
SpRay was developed during the master thesis of Julian Heinrich at the
Eberhard-Karls-Universität Tübingen and was originally targeted at the visual
exploration of gene expression data. SpRay is a generic visual analytics tool
using a tight integration of interactive visualization and the statistical
programming language R. See Linq was developed during the VAST ’09 contest by
Guido Reina and Christoph Müller at the Visualization Institute of Universität
Stuttgart (VISUS). It is based on a queryable model and employs .Net mechanisms
to integrate interactively formulated queries as data sources for linking and
brushing. The visualization was developed using rapid prototyping and supports
time-based events, and even though the glyphs are customized for this contest,
the visualization can be easily adopted to other tasks.
Video:
ANSWERS:
GC.1: Please describe the scenario supported by your analysis of the
three mini-challenges in a Debrief.
Here, we will show you what conclusions we’ve drawn on the basis of the
insights gained from our solutions to the three mini challenges.
There was an exchange of two suitcases visible on the
camera on Saturday 26th of January around 11:25 AM at location two.
A woman dressed in bright clothes and a man dressed in dark clothes exchanged
suitcases after talking for some time. The same woman met one man at 10:02 AM
and 10:32 AM, possibly the same person, and both times at location 4 of the
camera. The participants of the meeting could not be linked to a parked car. At
this day only 3 Persons entered the embassy and all of them were either in the
classified area or at their computer and generating network traffic.
There was a man with bicycle on Saturday 26th
around 08:51 AM at location 4, meeting another person and leaving the scene.
Shortly afterwards an employee entered the embassy.
From these facts we conclude that none of the
identified persons relating to the woman entered the embassy that day. While
exchanging suitcases is unusual by itself, the upload pattern described in the
following section adds to the interpretation that this exchange is related to
the case at hand. If this meeting had been the delivery of compensation, only
one suitcase would have been necessary. Two interpretations should be
investigated further. Money was exchanged against classified documents, or
documents were exchanged against forged documents. The embassy’s record should
be searched for documents that were handled by the suspicious employee of the
following sections.
The man with the bicycle could be an employee. If he
can be found in the embassy, he could be questioned about having seen a colleague
that day around the location of the suitcase exchange.
The destination IP 100.59.151.133 has high upload ratios and was
contacted from multiple computers in the embassy always on Tuesdays and
Thursdays except during the first week of the month. Many of the computers are
located around the office of employees number 30/31, but from the ID 30 there
was never an upload to this IP. Most of these uploads to this IP were executed
while the owner of the computer had “badged” into the classified area and not
yet “badged” out. Employee 30 was never in the classified area during these
uploads. The number and size of uploads grows steadily during the month. Two
days before the suitcase exchange, the owner of a computer resumed normal network
traffic only 3 minutes after the upload to 100.59.151.133 was executed.
Our interpretation is that the data requested by the criminal
organization was too much to be uploaded secretly, so that an exchange of
documents or a storage medium was agreed upon. The investigators should
question the owners of the used computers if they can report something
suspicious. A different possible interpretation would be that the uploader was
actually caught using employee 20’s computer and afterwards was blackmailed by
employee 20, as the use of other’s computers is a termination reason.
Scenario A can be matched very precisely on the flitter network. The
flitter user @schaffter that matches the role of an employee and the three
users @pettersson, @reitenspies, and @kushnir matching the role of handlers are
located in Prounov. The user @good matching the role of a middleman is located
in Kannvic and the user @szemeredi matching the role of the leader is located
in Kouvnic.
From this information we infer that the embassy is located in Prounov
and the handlers keep close contact to the employee. Together with the before
mentioned facts about upload patterns and the suitcase exchange, we suggest
that the exchange took place in Prounov. The woman probably met more than one
person of the network, which leads us to three possible scenarios:
1. The employee is female, thus the two or three different men she meets
could be her handlers. This requires verification against the embassy roster
whether employee number 30 is female.
2. One of the handlers is female and meets the male employee and the male
middleman, one of them probably twice. This could be to pass documents from the
employee to the middleman.
3. The middleman is female and meets two or three of her handlers, who are
male. Since the middleman does not live in ‘Prounov’, she is likely to meet
more than one of the handlers on the same day to reduce travel time.
We conclude with the most plausible scenario from our view:
The handlers of the criminal contact (@pettersson, @reitenspies, and @kushnir)
approached the embassy employee ID 30, known as @schaffter in flitter, during
the first week of January. They keep close contact to the employee and reside
at Prounov. On Tuesday the 8th @schaffter starts uploading
information from the embassy to a host controlled, hijacked or simply accessed
by the criminal organization. The handlers request more and more information
from @schaffter forcing him to take growing risks to upload data. On Thursday
the 24th, @schaffter’s activity was almost revealed. In addition to
further uploads during the next week, the employee had to deliver documents personally
on Saturday.
GC.2: Who are the major players in the scenario and what are their
relationships?
To identify suspicious
computer use, we first tried to identify irregular network traffic and then
related it to the badge log to single out the potential mole.
Using SpRay, we visualized
the connection matrix source/destination IP as tables and parallel coordinates.
The visualization reveals one connection count outlier, 37.170.30.250, and one
count that is extremely regular: 37.170.100.200 (Figure 1). Inspecting the
traffic itself in a table shows that only port 25 is used. Selecting this port
in the PC plot confirms that actually all mail traffic is directed at
37.170.30.250. We hypothesized that data theft via mail is too risky (usually
mail is logged), and thus exluded all mail traffic. Traffic to 37.170.100.200
is equally caused by all employee machines and its count in the linked table
approximately matches the number of working days in a month (20/21), therefore
it is probably not suspicious. Using the total upload size in the connection
matrix reveals another outlier in parallel coordinates: the top 13 uploads go
to 100.59.151.133, which we thereby define as suspicious.
Figure 1: Parallel coordinate plot linked
with R backend, displaying the connection count per destination address
To find a relation to the badge
traffic, we devised a visualization that presents IP traffic in context with
badge events (see Figure 2). Since our data model checks for basic consistency,
like a strict succession of prox-in-classified and prox-out-classified, we
found badges 38 and 49 as well as 30 to be inconsistent. The former two have
multiple presences in the classified room (missing prox-out-classifieds) and
the latter negative presence (missing prox-in-classifieds). We adjusted this by
inserting missing prox-out-classifieds just before the next prox-in-building
and missing prox-in-classifieds just after the previous prox-in-buildings
programmatically. These virtual events are visualized in red to invalidate the
potential ensuing suspicious traffic.
Figure 2: Badge and IP traffic visualized
together, X-axis represents time from left to right, Y-axis represents
employees
Figure 3: Top left: dataset with the
unmatched prox-in and prox-out-classified events caused by e.g. piggybacking.
Bottom right: after programmatic insertion of virtual events, the classified presence
of employees #30, #38, and #49 can be determined, but false positives for
network traffic on machine #30 appear (empty circles).
Highlighting the traffic to
37.170.100.200, it becomes evident that it is either caused by some kind of
login process or some bulletin system which, if accessed, every employee
accesses once a day as the first traffic from his machine. We verified this by
formulating an exact query to the underlying data model. If no access to this
machine occurs, the employee enters the classified room before generating any
IP traffic, so the necessary information must be available there as well. We
verified the 21 occurrences manually in the visualization. The remaining
exceptions are only three and represent uploads to the already suspicious
100.59.151.133.
Highlighting the remaining
15 uploads to 100.59.151.133, one can see in the visualization that some of
them happen while the computer owner is in the classified room. These uploads
are also conspicuously isolated. Hence we defined that the computer owner
probably did not trigger the uploads. We supposed that the mole does not
necessarily use his own computer to upload the stolen data to obfuscate his
actions. We wanted to find out which employee has enough time to trigger these
suspicious uploads. We defined a variable time before and after each upload
during which the suspect is not allowed to be in the classified room. Applying
this filter programmatically with a 2 minutes time before and after the upload,
only employees #27 and #30 remain. We manually examined the uploads for both
suspects and found that on 01/22, #27 entered the building after the upload and
also does not exhibit any other network traffic before badging in. Therefore
#27 is not the suspect.
Figure 4: Suspicious uploads to 100.59.151.133 along with inconsistent
traffic (circled). Inconsistencies for #30 stem from adjusted data. Only the
two potential moles, #27 and #30, are never in the classified room during these
uploads. The red box shows a magnification of the incident when the suspicious
upload on 01/22 happens before #27 enters the embassy.
For each upload event, we
then checked whether the suspicious uploads were conducted without the computer
owner or his/her roommate being present. Mostly potential disturbers are inside
the classified room or their machines generate no traffic for a significant
time, which we interpreted as absence. When #30 uses his neighbor's machine
(37.170.100.31), his own machine shows traffic regardless, which supports our
suspicion. On 01/24 there are two very risky uploads, with very little time to
complete the upload without being surprised by the machine owner or his
neighbor (10 minutes and 3 minutes). This might be in consequence of an
increasing talkativeness of the mole towards the end of the month: As the
amount of data transmitted per day increases by a factor of 3 between 01/08 and
01/31, more uploads from different machines are required to send everything.
However, all rooms are across the aisle from his own and we hypothesized at
least a semi-automatic upload process as to minimize the mole's time at another
machine (because of contract termination).
Figure 5: Spatial distribution of the
machines used to transmit data. Most of the machines are within easy reach from
the desk of employee #30.
Our conclusion is that
employee #30 is the mole who uploads classified information 18 times to
100.59.151.133 using 12 different machines.
We derive the following
patterns from our analysis:
- Mail traffic is too easy
to track and too risky for leaking confidential data
- Data theft is defined by
large RequestSize in the IP traffic
- Information is always
sent to the same destination
- Information is always
sent on Tuesday and Thursday.
- The mole never uses his
own machine for uploads
- The mole can only hijack
machines when alone (termination)
We also tried alternative
approaches to find additional suspicious uploads with programmatic queries:
- The obvious pattern of an
employee leaving the classified room and after a certain time t generating an
upload. Setting t to 10 minutes revealed no significant clusters of source or
destination. The highest uploads are individuals or machines that are commonly
accessed from at least half of the employee computers.
- We also tried to search
for the request/response ratio instead of the absolute of the request. Also in
this case the top ten traffic consisted of only commonly-accessed machines and
the already known 100.59.151.133. So this approach only confirmed our primary
suspect.
In order to find the structures outlined by the scenario descriptions in
the provided data set, we created a tool, partly reusing technology created in
previous projects. It restricts sets of entities (Flitter contacts in this
case) based on the number of contacts they have, optionally taking into account
the role of those contacts and supporting fuzzy rule definitions ("about
40 contacts"). Over the course of a few days, we adapted our tools for the
challenge and complemented them with new ones. We defined appropriate rules
formalizing the scenario descriptions. These rules include “an employee knows
roughly 40 contacts” or “a handler knows at least 1 middle man that at least 2
other handlers know”, for example. The creation of these rules took only a few
minutes.
We imported the provided data set into our tool and started with the
initial hypothesis that every person is a candidate for every role. This
results in 6000 candidates for each of the four primary roles ‘employee’,
‘handler’, ‘middle man’, and ‘leader’. By attaching rules to our starting
hypothesis node through drag&drop interaction, we created derived
hypotheses, thereby continuously reducing the sets of candidates by eliminating
those that do not meet the rules for the given scenario. The subsequently
applied rules comprise “an employee knows roughly 40 contacts”, “a handler
knows at least 1 employee”, “a handler knows roughly 30-40 contacts”, “a middle
man knows at least 3 handlers”, “a leader knows at least 1 middle man”, “a
leader knows at least about 125 contacts”, and ”an employee knows at least 3
handlers”. All of these rules were derived directly from the description of
scenario A. By requiring candidates to know “at least” as many contacts as
specified by the scenario, we were able to exclude those who know less and
therefore most certainly do not fulfill the role requirements. For example,
Flitter users with 20, 50, or even 80 contacts can be removed from the set of
possible ‘leaders’, as they do not meet the "well over 100 contacts” rule.
Many of the rules contain only approximate values, so we assigned confidence
values to the candidates, based on how well they meet a requirement. Because we
were looking for a structure that not necessarily satisfies all of the scenario
rules perfectly, we give the analyst the option to assign a weight value to
rules, determining the impact of a single rule on the confidence calculation.
The result is shown in the figure below.
Figure: The application of “safe
rules” reduces the possible roles for many entities. Starting from 6000 for
each role we get 116 / 298 / 775 / 22 candidates for employees (red) / handler
(green) / middlemen (cyan) / leader (magenta). The rule set on the right shows
available (brighter) and already used (darker) rules. Dropping a rule next to a
node creates a circular slider to adjust the weight of the rule and a node
representing the resulting candidate set.
Continuing from this point, we considered that a ‘middleman’ knows three
‘handlers’, the ‘leader’, at most one other member of the criminal
organization, and no one else. As confirmed by a blog answer, "no one
else" refers to the entire Flitter network, so we added the rule “a
middleman knows roughly 4-5 contacts”. Noticing that the substantial reduction
of ‘middlemen’ did not affect the number of ‘handler’ candidates, we added the
rule “a handler knows at least 1 middle man”, which left us with a set small
enough to be visualized as a graph.
Figure: Possible criminal
networks can be displayed by hovering over an entity. This network is
incomplete because the ‘middleman’ (cyan) is not in contact with any ‘leader’
candidate.
The entities are laid out according to their roles. Entities which are
candidates for more than one role are represented by multiple visual items.
Pointing at an entity highlights its links to the adjacent layers and uncovers
that there are ‘middlemen’ without any connection to a ‘leader’ candidate.
Adding this last rule ("a middle man knows at least one leader")
results in the two possible networks shown below.
Figure: Two possible criminal networks.
The highlighted one does not fully comply with the description because two of
the handlers know each other.
In one of these networks, two of the ‘handlers’ (@bailey and @letelier)
know each other, which contradicts the scenario description. Right clicking
@bailey and explicitly stating that he or she "is not a handler"
removes the respective network from the hypothesis (by means of rules that are
still in effect but can no longer be met if @bailey is no ‘handler’). This
leaves only one network with @shaffter as the ‘employee’ and @szemeredi as the
‘leader’. This result fulfills every aspect of the description of scenario A
perfectly and is our primary solution.
The international contacts of the persons involved in the network can
easily be investigated by brushing over the candidate network view. All
highlights are directly reflected in the linked map display. We see that the
employee and the three handlers are in ‘Prounov’, the middleman is located in
‘Kannvic’, and the leader is in Kouvnic
We then considered the slightly different description of scenario B,
which states that “each of the middle men probably communicates with one or two
others in the organization, and no one else”. In this context, this translates
to “a middleman has 2-3 contacts” (one handler plus 1-2 others). However, as
the minimum number of contacts for any user is 4, this rule would eliminate all
‘middleman’ candidates. Applying other “safe” rules reduces the candidate set
to 3 names that have only 4 contacts, but assuming any of them as a ‘middleman’
does not result in the expected network structure. Strictly applying the other
criteria excludes all potential result networks that have the correct number of
contacts for ‘employees’ and ‘handlers’.
Location: 4 Start Time: 7:01:13 Duration: 3:59
A dark dressed man and a woman with a bright coat, bag and hat are
talking to each other.
The man and the woman are also meeting in the video sequence at 7:31:05.
This is a suspicious event,
since the woman is also involved in the briefcase exchange in 8:23:57.
Location: 4 Start Time: 7:31:05 Duration: 1:29
The already mentioned persons (woman & man from meeting at 7:01:13)
are talking.
Maybe this is another meeting to negotiate time and location of the
subsequent briefcase transfer.
Location: 2 Start Time: 8:23:57 Duration: 5:00
A black dressed man with a white briefcase meets the before mentioned
white dressed lady. She carries a black briefcase.
After talking a few minutes they exchange their briefcases and leave the
scenery. It looks like both people walked to their meeting place,
since there is no relevant change of the cars parked at the road. The
woman leaves to the same direction as she came from.
Location: 1 Start Time: 0:45:20 Duration: 0:15
A person fetches an object out of the red van and gives it to the other
person.
The red van stood in this parking area since the first frame of the
video capture.
After the transfer the red van is driven away. This event is interesting
because of the object transfer.
Location: 4 Start Time: 5:50:47 Duration: 3:46
A man with white clothes and a bike waits for someone. Another person
dressed in blue, arrives and they're talking to each other for a while.
This meeting is interesting because of its length and the fact that one
of the men goes by bicycle – recall that the embassy is in walking range.
Location: 1 Start Time: 9:13:49 Duration: 17:43
A person is getting seated at 9:10:15 and another person joins at
9:13:19.
They're talking to each other for about 17 minutes. After that they're
leaving and say goodbye.
Location: 2 Start Time: 7:13:00 Duration: 6:30
Two people talk to each other, one is clothed in red. After the meeting
the red person is walking alone at 7:21:46.
Location: 2 Start Time: 2:52:19 Duration: 0:15
Two persons are talking to each other and are leaving in different
directions after saying goodbye.
This indicates the end of a meeting, but especially there is nothing
more suspicious.
Location: 1 Start Time: 0:08:03 Duration: 2:41
A person leaves a house and carries a briefcase to a car (captured by all
camera positions). Then he returns to the house.
This event gets interesting in the context of the briefcase exchange at
Saturday.
But this man doesn’t seem to be the man directly involved in the
exchange – he carries the briefcase with the left hand (in contrast to the man
at 8:23:57).
The basic idea of our approach is to identify the
encounter of people by their movement trajectories. The characteristics of
these trajectories should help us to localize relevant parts of the sequence
and though yield to a scalable method.
First, we separated the video sequence by an automated
preprocessing step into the four locations, the camera captured. This
preprocessing step also extracts the trajectories and calculates several
additional properties.
The information include camera location, scene number,
the temporal start and end positions, spatial positions of the tracks in pixel
coordinates as well as spatial positions perspective projected to the ground,
the mean speed and average direction.
For fast video exploration and filter interaction an
easily operable visualization tool is necessary. Fig. 1 shows this tool and its
visualization of the different camera positions as a 3D volume with time as
third axis.
We can see a few keyframes and trajectories of
detected objects. The blue bar indicates the time passed between two visualized
scenes.
Between two scenes there is always a gap for at least
58 – 61 sec which originates from the camera movement. If we apply a filter
this time may increase, as we see in the left column of Fig.1. For accelerated
exploration, all scenes without any objects of interest are hidden.
Figure 1
Starting with the exploration of the trajectories it
turns out, that many of them belong to cars driving on the street. Since these
objects are not of interest to us, we define a filter omitting these
trajectories (Fig.4, right / Fig.2).
Figure 2
Based on further information of the remaining object
trajectories, which were obtained by graphical user interaction (Fig.3), the
visualization tool allows us to remove also some false detections originating
from highly variant video parts.
Figure 3
While exploring the video, it pointed out, that many
trajectories are leading from people just crossing the scene or waiting at the pedestrian
crossing (Fig. 4, left). We have also rejected these.
Figure 4
Finally we added our strongest hypotheses to the filter system, the
interaction of multiple trajectories.
The trajectories of meeting people should begin with a merging stage
then bend over to a stage of steady movement, before diverging in a trajectory
split.
Filtering for one of these stages heavily decreases the amount of
remaining trajectories. Fig. 5 depicts a splitting scenario. In this case a
woman and man,
as described earlier in this section, meet each other, and leave in
different directions after exchanging briefcases. This classification of the
meaning of the scene
could only be done by human.
Since this is a very suspicious and Hollywood-like scene we rate it as
the AAA-espionage event contained in this sequence. Further meeting of the
woman involved in this encounter are also detected with this system.
Figure 5
Starting from the point of the separately extracted data from the mini
challenges we will show now how we combined the facts to deal with the grand
challenge.
First of all we will summarize the facts of the mini challenges to help
following our inference.
Our discovered assertions are:
MC1:
1. We identified the IP address 100.59.151.133 as possible destination for
uploads of suspicious data.
2. Traffic to this IP took place only on Tuesdays and Thursdays.
3. We identified the employee with the ID 30 (“the mole”) to be the person
responsible for this traffic.
4. The mole used the computers of colleagues that were not in their offices
during the upload events (they were either in the classified area or at home)
MC2:
1. The identified employee and the three handlers in the flitter network
are based in ‘Prounov’, so we assume the embassy is located there, too.
2. There is one middleman. He is based in ‘Kannvic’.
3. The identified leader is in ‘Kouvnic’
MC3:
1. There was an exchange of two suitcases on Saturday 26th of
January around 11:25 am, at location two.
2. A bright-dressed woman with a hat and a purse has met a dark-dressed man
for this exchange.
3. The same woman met one, or probably two different, men at 10:02 am and
10:32 am, both at location 4.
Our first step was to formulate a request in our badge
traffic tool to check the time of the suitcase transfer. This led us to the
fact that the mole was not in the embassy this day.
With this request we also enforced our assertion that
ID 30 is the mole (if she would have been in the embassy to the same time the
transfer was, our hypothesis would have been rejected)
After that we formulated a new request to the badge/network
traffic tool to check if there are any exceptional occurrences in the network
traffic on the days right before the meeting.
We saw that the uploads to this address increased
steadily in number and volume until the end of the month (see Fig. 1 left).
Figure 2
The uploads had a higher risk factor, too. We got focused
to the uploads two days before (Thursday the 24th):
The mole committed three risky uploads, where the
owner of the computers only left for a short time. The mole just got away from
the owner of the computers right before he came back. Maybe the mole was even caught in the act by
employee #20 (upload from the mole at 17:07, normal use by employee #20 just
three minutes later at 17:10, see Fig. 1 right)
This brought us to form a panic hypothesis:
The amount of data, requested by the criminal
organization, was too much to be uploaded secretly, and therefore the suitcase
exchange was initiated.
This would also release the question why the suitcase
transfer is needed in our digital age. Maybe several physical documents would
have taken too much time to digitize first.
Next we had a look at the social network results with
our suitcase transfer information in mind: The handlers and the employee live
in the same town. Because of that we checked in the video if the parking cars
captured by the camera changed right before or after the transfer. They did
not, so maybe both, the woman and the man from the suitcase transfer, live in
the same town and got to the meeting place by foot. But this could also be
false: They could arrive by train, plane or could just have parked their cars
far away to stay incognito.
Another event from the video happened on Thursday 24th
at 10:08 AM. A man left a building in location 4 with a suitcase. He walked
through all locations captured by the camera, put the suitcase into a car and
went back to the building. We formed the hypothesis that the building he left
is the embassy. To check this hypothesis we checked the entrance time of this
man with our badge/network tool for consistency. It matched. So we formed a
position filter in the video analysis tool to get all events with people
entering and leaving this building. We checked these timestamps with the badge/network
tool again. The entry times did not fit the entry times in our video. Our
hypothesis was rejected; the building is not the embassy.
One more event could be seen in the video: On Saturday
26th at 8:51 AM a man arrived with a bike and had a short talk with
another man. He left a few minutes later and we checked the badge traffic for
this time. A few minutes later someone arrived in the embassy. Maybe the man
with the bike is an employee and saw some of his colleagues at location 4.
Maybe it could be possible to ask him if he saw some of his colleagues this
morning and to get some information from him.
Another request aimed at the information that at least
one woman must be inside the criminal network. We checked our flitter network
for nicknames that suggest to be created by a woman, but we didn’t find
manifestations of this case.
We tried to map IP-Addresses to Locations. Therefore
we compared the subnet domains from the IP-traffic scenario with the cities of
the flitter network, but we were not able to map the subnets to cities. Either
we had more subnets than cities or vice versa.
Another hypothesis we assumed was that port 8080 is
used to communicate via flitter. This port is used sparsely and the suspicious
uploads were made through it. With the basis of this assumption we took a
further look at the IP-Addresses contacted from port 8080 and tried to map the
IP-Addresses of the handlers to the flitter IDs. However, we could not derive
any connection of this type.
The most suspicious event in the video is the exchange of two suitcases.
This particular event leads to the assumption that at least one woman must be
involved. From the social structure of the flitter network, we know that we are
dealing with 1 employee and 3 handlers, based in the same city, plus one
middleman. Combining this with the badge data and the identified employee
numbers, we can formulate the following three hypotheses (see also Fig. 2):
A. The employee is female,
thus the two or three different men she meets could be her handlers. This requires
verification against the embassy roster whether employee number 30 is female or
not.
B. One of the handlers is
female and meets the male employee and the male middleman, one of them probably
twice. Here the question arises why the employee has not entered the embassy
and stolen the documents on the Saturday of the footage, since he could be
fairly sure to be undisturbed. However, we could not detect suspicious traffic
on this particular day.
C. The middleman is female
and meets 2 or three of her handlers, who are male. Since the middleman does
not live in ‘Prounov’, she is likely to meet more than one of the handlers on
the same day to reduce travel time. However, there was no related car movement
in the video. We have no further information on this scenario.
Figure 2