arXiv subjects

Kevin van Liebergen

Publications and source records attributed to Kevin van Liebergen.

3 recordsLinked to original sources

arXiv2025

Clean Up the Mess: Addressing Data Pollution in Cryptocurrency Abuse Reporting Services

Cryptocurrency abuse reporting services are a valuable data source about abusive blockchain addresses, prevalent types of cryptocurrency abuse, and their financial impact on victims. However, they may suffer data pollution due to their crowd-sourced nature. This work analyzes the extent and impact of data pollution in cryptocurrency abuse reporting services and proposes a novel LLM-based defense to address the pollution. We collect 289K abuse reports submitted over 6 years to two popular services and use them to answer three research questions. RQ1 analyzes the extent and impact of pollution. We show that spam reports will eventually flood unchecked abuse reporting services, with BitcoinAbuse receiving 75% of spam before stopping operations. We build a public dataset of 19,443 abuse reports labeled with 19 popular abuse types and use it to reveal the inaccuracy of user-reported abuse types. We identified 91 (0.1%) benign addresses reported, responsible for 60% of all the received funds. RQ2 examines whether we can automate identifying valid reports and their classification into abuse types. We propose an unsupervised LLM-based classifier that achieves an F1 score of 0.95 when classifying reports, an F1 of 0.89 when classifying out-of-distribution data, and an F1 of 0.99 when identifying spam reports. Our unsupervised LLM-based classifier clearly outperforms two baselines: a supervised classifier and a naive usage of the LLM. Finally, RQ3 demonstrates the usefulness of our LLM-based classifier for quantifying the financial impact of different cryptocurrency abuse types. We show that victim-reported losses heavily underestimate cybercriminal revenue by estimating a 29 times higher revenue from deposit transactions. We identified that investment scams have the highest financial impact and that extortions have lower conversion rates but compensate for them with massive email campaigns.

cs.CR↗

arXiv2023

Cybercrime Bitcoin Revenue Estimations: Quantifying the Impact of Methodology and Coverage

Multiple works have leveraged the public Bitcoin ledger to estimate the revenue cybercriminals obtain from their victims. Estimations focusing on the same target often do not agree, due to the use of different methodologies, seed addresses, and time periods. These factors make it challenging to understand the impact of their methodological differences. Furthermore, they underestimate the revenue due to the (lack of) coverage on the target's payment addresses, but how large this impact remains unknown. In this work, we perform the first systematic analysis on the estimation of cybercrime bitcoin revenue. We implement a tool that can replicate the different estimation methodologies. Using our tool we can quantify, in a controlled setting, the impact of the different methodology steps. In contrast to what is widely believed, we show that the revenue is not always underestimated. There exist methodologies that can introduce huge overestimation. We collect 30,424 payment addresses and use them to compare the financial impact of 6 cybercrimes (ransomware, clippers, sextortion, Ponzi schemes, giveaway scams, exchange scams) and of 141 cybercriminal groups. We observe that the popular multi-input clustering fails to discover addresses for 40% of groups. We quantify, for the first time, the impact of the (lack of) coverage on the estimation. For this, we propose two techniques to achieve high coverage, possibly nearly complete, on the DeadBolt server ransomware. Our expanded coverage enables estimating DeadBolt's revenue at $2.47M, 39 times higher than the estimation using two popular Internet scan engines.

cs.CR↗

arXiv2022

A Deep Dive into VirusTotal: Characterizing and Clustering a Massive File Feed

Online scanners analyze user-submitted files with a large number of security tools and provide access to the analysis results. As the most popular online scanner, VirusTotal (VT) is often used for determining if samples are malicious, labeling samples with their family, hunting for new threats, and collecting malware samples. We analyze 328M VT reports for 235M samples collected for one year through the VT file feed. We use the reports to characterize the VT file feed in depth and compare it with the telemetry of a large security vendor. We answer questions such as How diverse is the feed? Does it allow building malware datasets for different filetypes? How fresh are the samples it provides? What is the distribution of malware families it sees? Does that distribution really represent malware on user devices? We then explore how to perform threat hunting at scale by investigating scalable approaches that can produce high purity clusters on the 235M feed samples. We investigate three clustering approaches: hierarchical agglomerative clustering (HAC), a more scalable HAC variant for TLSH digests (HAC-T), and a simple feature value grouping (FVG). Our results show that HAC-T and FVG using selected features produce high precision clusters on ground truth datasets. However, only FVG scales to the daily influx of samples in the feed. Moreover, FVG takes 15 hours to cluster the whole dataset of 235M samples. Finally, we use the produced clusters for threat hunting, namely for detecting 190K samples thought to be benign (i.e., with zero detections) that may really be malicious because they belong to 29K clusters where most samples are detected as malicious.

cs.CR↗