Detecting Complex Money Laundering Patterns with Incremental and Distributed Graph Modeling
Authors: Haseeb Tariq, Alen Kaja, Marwan Hassani
Organizations: ING Bank Amsterdam, The Netherlands · Eindhoven University of Technology Eindhoven, The Netherlands · Identity & Risk Intelligence Adyen Amsterdam, The Netherlands · Mathematics & Computer Science Eindhoven University of Technology Eindhoven, The Netherlands
Money launderers take advantage of limitations in existing detection approaches by hiding their financial footprints in a deceitful manner. They manage this by replicating transaction patterns that the monitoring systems cannot easily distinguish. As a result, criminally gained assets are pushed into legitimate financial channels without drawing attention. Algorithms developed to monitor money flows often struggle with scale and complexity. The difficulty of identifying such activities is further intensified by the (persistent) inability of current solutions to control the excessive number of false positive signals produced by rigid, risk-based rules systems. We propose a framework called ReDiRect (REduce, DIstribute, and RECTify), specifically designed to overcome these challenges. The primary contribution of our work is a novel framing of this problem in an unsupervised setting; where a large transaction graph is fuzzily partitioned into smaller, manageable components to enable fast processing in a distributed manner. In addition, we define a refined evaluation metric that better captures the effectiveness of exposed money laundering patterns. Through comprehensive experimentation, we demonstrate that our framework achieves superior performance compared to existing and state-of-the-art techniques, particularly in terms of efficiency and real-world applicability. For validation, we used the real (open source) Libra dataset and the recently released synthetic datasets by IBM Watson. Our code and datasets are available at https://github.com/mhaseebtariq/redirect.
Figures & tables
Fig. 1 : Conceptualization of the problem formulation for ReDiRect . Left side represents the actual data space; in the next part, nodes are filtered out, either by the primary detection system; or by the output of an earlier ReDiRect run. Finally, the fuzzy communities (per node) are labeled as suspicious by an unsupervised machine learning model.
Anomalies
Count
Threshold
Count / Actual (Threshold Factor)
Actual
600
–
1.00
Top 0.1%
385
T1
0.64
Top 0.2%
770
T2
1.28
Top 0.5%
1926
T3
3.21
Top 1%
3851
T4
6.42
TABLE I : Thresholds used in [ 9 ] to select the top anomalies. The top-x% (predicted anomalies) is calculated from 385,100 accounts.
Dataset
Total
T1 (0.64)
T2 (1.28)
T3 (3.21)
T4 (6.42)
Dlibreal
600
385
770
1926
3851
Dibmsyn LI
1360
873
1745
4366
8729
Dibmsyn HI
9664
6201
12402
31021
62027
TABLE II : Thresholds used in [ 9 ] for Dibmsyn large datasets. LI = Low-Illicit; HI = High-Illicit.
Fig. 2 : Example alerted flow: The yellow are extra (or false-positive); and the red are missing (or false-negative) nodes. The contextual completeness would be → 7 (correctly alerted context) / 11 (alerted with missing context) = 0.64.
TABLE III : Summary of an example ML (money laundering) flow: transactions, maximum ML share (or contribution), and detection scenarios. Scenario 2 has better context-weighted recall than Scenario 1.
Fig. 3 : TPR AUC plots comparing the initial run of ReDiRect (no reduction in data), with the outputs of RM-2 (10% reduction) and RM-3 (12.5% reduction) methods.
Mean ILT (Investigation Lead Time)
Method
Threshold Factor
Actual
T1
T2
T3
T4
EgoNetRed [ 9 ]
12.4
102.84
67.24
37.62
23.59
ReDiRect 100%
8.35
23.24
23.49
21.11
17.54
[RM-2] 75%
8.33
23.36
23.4
20.34
16.59
[RM-2] 40%
7.99
21.72
21.4
17.48
13.63
TABLE IV : Mean investigation lead times. Bold font represents the best times. Cells with shaded background represent variations of ReDiRect .
Alerts
Reports
Method
AUC- T4
TPR- T1
TPR- T2
TPR - T3
TPR - T4
AUC- T4
TPR- T1
TPR- T2
TPR- T3
TPR- T4
EgoNet [ 1 ]
0.599
0.287
0.437
0.660
0.815
0.574
0.146
0.336
0.672
0.850
EgoNetRed [ 9 ]
0.604
0.405
0.514
0.660
0.744
0.603
0.355
0.437
0.696
0.772
ReDiRect 100%
0.617
0.364
0.524
0.660
0.791
0.676
0.318
0.546
0.727
0.955
—"—[RM-2] 75%
0.623
0.364
0.527
0.670
0.804
0.674
0.318
0.546
0.727
0.955
—"—[RM-2] 40%
0.634
0.374
0.529
0.696
0.819
0.653
0.318
0.409
0.727
0.955
TABLE V : Detailed evaluation results on the Dlibreal dataset. Bold font represents the best version. Red font is when ReDiRect is better than the competitors.
Method
Threshold Factor
T1
T2
T3
T4
[LI] RM-1
0.034
0.075
0.190
0.351
[HI] No reduction
0.050
0.087
0.271
0.450
[HI] RM-1
0.287
0.498
0.675
0.713
[HI] RM-2 50%
0.237
0.477
0.658
0.683
TABLE VI : Context-weighted recall for the Dibmsyn datasets. LI = Low-Illicit; HI = High-Illicit.
p
n
Total
Actual
p’
369
149
518
n’
3497
63063
66560
Total
3866
63211
TABLE VII : Context-weighted confusion matrix for Dibmsyn (high-illicit) [RM-1], with T4 selection threshold.
Fig. 4 : The execution times for each of the heavy duty tasks in the framework, with increasing number of nodes in the Dlibreal dataset.
Fig. 5 : Execution times for Dibmsyn large dataset, with increasing level of distribution.
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